Floriculture Greenhouse Update

Nature seems to be getting more violent in recent years with frequent earthquakes, increased numbers of hurricanes and record breaking snowstorms.  Insurance damage claims have increased considerably.  The International Building Code has revised upward its wind and snow loading requirements for some areas of the U.S.  Each year there are reports of greenhouses that have been damaged by weather and natural events.  Greenhouse design is different than conventional farm buildings in that the structural profile has to be small to allow maximum light to reach the plants. Most farm buildings are over designed to handle severe weather conditions.Storm damage to greenhouses can include racking of the frame, bending of the hoops, broken glass or torn plastic and uplifted foundation posts.  Preparation ahead of time can minimize the damage.Wind loadingWind forces that act on a greenhouse are influenced by numerous factors including the basics wind speed, building orientation, exposure, height and shape of doors or vents that may be open.  The wind passing over a greenhouse creates a positive pressure on the windward side and a negative pressure on the leeward side.  These can combine to create a force that wants to collapse or overturn the building.  An 80 mph wind can produce a pressure of 16 pounds per square foot (psf).  For example, the 10' by 100' sidewall of a gutter-connected greenhouse would have to resist a 16,000 pound force.Wind can also create a force similar to an aircraft wing that wants to lift the greenhouse off the ground.  An 80 mph wind blowing perpendicular to the side of a 28' x 100' hoophouse can create a lifting force of 220 pounds per foot of length or 22,000 pounds of uplift on the whole structure.  When you consider the total weight of materials and equipment in the greenhouse is about 6000 pounds, the foundation must have a withdrawl resistance of about 300 pounds each.  This is why building inspectors frequently require that the posts be surrounded by concrete.Although you have no control over the force or direction of severe winds, here are a few tips to help minimize storm damage:

• Check the area for loose objects.  Anything that can be picked up and hurled through the glazing should be secured or moved indoors.  Metal chimney (stove pipe) sections should be secured with sheet metal screws.
•  Inspect for dry or weak tree limbs that could fall on the greenhouse.
•  Close all openings including vents, louvers and doors.  The effective force of the wind is doubled when it is allowed inside the building.  The wind on the outside puts a pressure or lifting force on the structure.  The wind inside tries to force the walls and roof off.
•  On air inflated greenhouses, increase the inflation pressure slightly by opening the blower’s intake valve.  This will reduce the rippling effect.  Check to see that the plastic is attached securely and that any holes are taped.
•  Disconnect the arm to the motor on all ventilation – intake shutters and tape the shutters closed.  Then turn on enough exhaust fans to create a vacuum in the greenhouse.  This will suck the plastic tight against the frame.
•  Windbreaks can reduce the wind speed and deflect it over the greenhouse.  Conifer trees (hemlock, spruce, pine, etc.) in a double row located at least 50' upwind from the greenhouse can reduce the damaging effects of the wind.  Wood or plastic storm fencing can be used as a temporary measure.

John Bartok, Extension Professor Emeritus and Ag Engineer, UConn

Fact Sheet: Reducing Storm Damage to Your Greenhouses (includes snow loading also)

Note: With wind, rain and cooler temperatures, growers are advised to continue inspecting plants and use preventative sprays for diseases such as Downy mildew on basil and Chrysanthemum white rust on garden mums.  Leanne Pundt, UConn

Late Blight caused by Phytophthora infestans – a very destructive and very infectious disease killed tomato and potato plants in gardens and on commercial farms throughout the eastern U.S. during 2009. Late blight occurs at some locations in the Northeast each year, however in 2009 infected plants were distributed through large local retail stores throughout the region (Ohio to Maine) during June, and outbreaks were reported over this entire region by early July. Never before had such an extensive distribution of infected plants occurred, especially so early in the season. This, combined with the cool, wet growing season and the exceptionally contagious nature of the disease during cool, rainy, windy weather all contributed to a disastrous year for farmers. Garden retailers can help prevent the spread of late blight in gardens and on farms this growing season and provide customers with the facts about this disease. Grow your own transplants from seed or purchase locally grown plants Late blight is not seedborne in tomatoes (however, it is tuber-borne in potato), so tomato plants started from seed locally would be free of the disease. Growing your own transplants from seed or purchasing from a reputable local grower will ensure a healthy start to the season for your customers and local farms. Provide disease-resistant or tolerant varieties       Tomatoes: Disease-resistant or tolerant varieties of tomatoes exist, however seed is in limited supply this year. ‘Mountain Magic’, ‘Plum Regal’, and ‘Legend’ are three varieties with resistance or tolerance to late blight. Note that the variety ‘Legend’ is the only late-blight resistant variety for which seed is readily available this year. In addition to late blight, each year tomatoes become infected with early blight and Septoria leaf spot, which look very similar. If possible, also provide tomato plant varieties that are resistant or tolerant to early blight for your customers, such as the varieties ‘Mountain Fresh’, ‘Mountain Supreme’, and ‘Plum Dandy’ and others.       Potatoes: Purchase certified, disease-free seed potato from a reputable source, and ask your supplier about their source of seed and if it was inspected in the field for late blight. Seed potato from the northeast are less likely to carry the disease. Inspect transplants for signs of disease If you purchase plants to sell, inspect all transplants for stem, petiole cankers or leaf blight as long as plants are on the shelf. Teach your staff what to look for, using the web-links below. If you suspect a late blight infection, use your Plant Diagnostic Lab to confirm if late blight is present. Know the FACTS for Staff and Customers Train employees and provide information to your home gardening customers. * Potatoes that freeze or fully decompose will not carry the pathogen over winter. * Tomatoes will not carry late blight over the winter, because freezing kills the whole plant. *  Tomato seed, even from fruit that was infected with late blight, will not carry the pathogen, so no need to worry about the tomatoes left behind in the garden or compost pile. Certain perennial weeds can become infected with late blight, but none of their above-ground tissues live through the winter. *  Late blight will not survive on tomato stakes and cages. * The biggest threat for overwintered disease in New England is on potatoes. In the spring, advise home gardeners to inspect last year’s potato plot and any compost or cull piles for volunteer potato plants that might come up. If they find potato plants, pull them out and put them in the trash or destroy them. If tubers were infected and survive, then the late blight could grow upward from the tuber, infecting the stem and producing spores when weather conditions are favorable. These spores could then disperse to other tomato and potato plants. * During the growing season, pay attention to pest alerts to learn about whether late blight has been observed in New England, and what actions you need to advise to customers. Pest alerts will be updated on the UMass Extension Vegetable Program Website, www.umassvegetable.org   

Photos: Symptoms on stems, leaves and fruit (Cornell) Photos, FAQ, Fact Sheets (Cornell)

Tina Smith, University of Massachusetts

USDA Natural Resources Conservation Service (NRCS) will provide financial assistance for a new pilot project to establish high tunnels to increase the availability of locally grown produce in a conservation-friendly way. This is being done through their Environmental Quality Incentives Program (EQIP). Participating farms can receive funding for one high tunnel up to approximately a 30 by 72 foot structure. Farmers in New England and New York who would like to sign-up for the high tunnel pilot, should call or visit their local NRCS office by January 15, 2010.

Here is the complete newsrelease and links for more information.

Tina Smith, University of Massachusetts Leanne Pundt, University of Connecticut

When choosing plants for retail sale, trial gardens can help growers decide which plants to grow and provide information to customers. Dr. Douglas Cox, University of Massachusetts reported some observations on some new and recent introductions made on plants growing in a small trial garden run by Durfee Conservatory at UMass, trial gardens at Elm Bank, Dover, MA and plantings of his own in Sunderland, MA.    

Here are excerpts from the article: Alyssum ‘Snow Princess’ (Vegetative) The heat tolerance was hard to evaluate the summer, but ‘Snow Princess’ did indeed have a long flowering season starting at planting in mid-May through to October. We cut our plants back once and they quickly recovered to rebloom very well. Plants are compact (4-6” tall) and are excellent spreaders. Angelonia ‘Serena’ (Seed) ‘Serena is not a new plant but it remains the principal seed-propagated Angelonia. In my opinion, the two best characteristics of Angelonias are the vigorous and continuous blooming once the plants are established and the long life of each flower stalk which can extend many weeks. Based on my experience it’s clear that success with ‘Serena’ starts with seeding. Germination temperature should be 68-70°F and irrigation should be carefully managed to avoid overwatering. Seed should not be covered. Angelonias are often thought of as heat-loving plants. Over the years I have found that cool temperatures at planting outdoors do slow development of ‘Serena’, but by the middle or end of June, the plants really take off. Gomphrena ‘Fireworks’ (Seed) I think Gomphrenas are very useful garden plants because they require very little maintenance, minimal deadheading, and the individual flowers last for may weeks. ‘Fireworks’ is a much larger plant and has larger flowers than the familiar Gomphrenas. This plant may be a tough sell to the average consumer because these plants in packs and small containers may be too small to flower, so some promotion with pictures may be necessary. Read more about trial results with photos in the complete article including Cuphea ‘Matchmaker’, Ipomoea ‘Illusion Emeral Lace’ and ‘Midnight Lace’, Petunia ‘Pretty Much Picasso’, Zinnia ‘Solcito’ and Zinnia ‘Zahara’. Note that the companies in the article are the sources of plant material for the trials and are not necessarily that of the breeder.

Elm Bank Trial Gardens: David Fiske is the trial garden manager at Elm Bank.

Integrated pest management practices such as inspecting incoming plants, weekly monitoring, sound cultural practices, pest identification and problem diagnosis are just as important for retail greenhouses as production greenhouses.

Inspecting incoming plants is the most important method to prevent problems from developing in retail operations. If at all possible, do not accept plant shipments with serious insects or diseases with wide host ranges, and are difficult to treat. If you find isolated evidence of some insect activity, for example, aphids, and decide to keep the shipment, identify an isolated, quarantine area in which to keep the plants. Treat immediately and hold the plants in this area until you are sure that they are healthy, salable and free of pest problems.

The weekend weather forecast calls for sunny days with temperatures in the mid to high 80’s following this week of cool, cloudy weather. As a result, there is a strong possibility, your spring crops will experience summer temperatures in a greenhouse with little or no shading in place. Even one or two days of bright sunshine with temperatures in the high 80’s can stress bedding plants and hangers with rooting systems that are not fully developed. Delicate foliage of shade plants such as impatiens will be susceptible to sunburn.

Be sure your greenhouses are well ventilated and the crops are irrigated to avoid wilting and undue stress on the crops. Shade cloth may be needed over areas containing shade plants.

Photo: Impatiens showing stress

Sunscald on Basil

Tina Smith, Paul Lopes, University of Massachusetts

As you gear up for the growing season, be sure to carefully read pesticide labels before purchasing a new product. Some products with different trade names have the same active ingredients. Some products may have different active ingredients, but have the same mode of action (MOA). Growers will see more generic products on the market as pesticides come off patent, which can make choosing pesticides very confusing. There are now many different products containing imidacloprid, abamectin, bifenthrin, permethrin, chlorothalonil and thiophanate methyl.  Growth regulators containing paclobutrazol include Bonzi, Piccolo, Paczol and Downsize. Read labels carefully since there are similarly named products that may have slightly different concentrations of active ingredient.

A good example is Banrot which contains the active ingredients thiophanate methyl & etradiazole, the same active ingredients as Cleary's 3336 (thiophanate methyl) and Truban (etradiazole). Different formulations (flowable, wettable powder, emulsifiable concentrate etc.) of products often contain different concentrations of active ingredient. Both Cleary's and Truban are available in various formulations. Over-application of a pesticide, especially emulsifiable concentrates (EC) and surfactants can cause phytotoxicity. 

Continued use of products with the same mode of action can lead to pesticide resistance. To help delay pesticide resistance, rotate pesticides with different modes of action (MoA).  Most pesticides have a number on the label that correlates with their mode of action group to make it easier to recognize the MoA for rotation.  This can be found on the website below or in the New England Greenhouse Floriculture Guide   Unless directed on the pesticide label, switch to a insecticide or miticide with a different mode of action about every 2 to 3 pest generations, or about every 2-3 weeks, depending on temperature and length of insect or mites life cycles. 

Resistance also develops when fungi are repeatedly exposed to fungicides with a single site mode of action (systemic fungicides).  It requires very little genetic change in fungus populations for resistance to develop.  Protectant fungicides are less likely to develop resistance problems for they have multi-site modes of action (MoA). To help prevent the development of resistance, alternate applications among different MOA groups, or mix or rotate systemic/protectant fungicides. 

Pesticide labels, material safety data sheets (MSDS), mode of action and related information can be found on the following websites:

Greenbook/C&P Press, Inc. www.greenbook.net

CDMS, Inc http://www.cdms.net/LabelsMsds/LMDefault.aspx

Kelly Registrations Systems, Inc. (pesticide registrations) www.kellysolutions.com  

IRAC Mode of Action Classification www.irac-online.org  

FRAC Codes www.frac.info/frac/index.htm

Tina Smith, University of Massachusetts Leanne Pundt, University of Connecticut

It's that time of year when Oriental bittersweet berries are in abundant supply and show up as wreaths, swags and in other decorative crafts for sale at roadside stands and other retail outlets. This is just a reminder that bittersweet (Celastrus orbiculatus) is considered an invasive plant along with purple loosestrife (Lythrum salicaria), yellow iris (Iris pseudacorus) and many others. Connecticut has 96 plants on the official state list that are invasive or potentially invasive and 81 of those are banned. Massachusetts has 140 plants identified as either noxious and/or invasive that are banned. In MA a few woody ornamentals have an extension until January 1, 2009. When choosing plants to grow and sell and when using plant material for crafts, obtain a list of prohibited plants from your state Department of Agriculture. Noxious and/or invasive plants are prohibited from being sold, traded, purchased and distributed. Invasive plants, as defined by the Massachusetts Invasive Plant Group, are "plants that have spread into native or minimally managed plant systems in Massachusetts. These plants cause economic or environmental harm by developing self-sustaining populations and becoming dominant and/or disruptive to those systems." For a list of prohibited plants in Massachusetts and Connecticut and for more information, see the websites below.

USDA National Invasive Species Information Center:  Massachusetts   Connecticut  (Other States)

Massachusetts Department of Agricultural Resources - Massachusetts Prohibited Plants

Massachusetts Nursery Landscape Association (Includes alternative plants)

Connecticut Invasive Plant Working Group

Purple Loosestrife Biological Control Projects Massachusetts: Massachusetts Wetlands Restoration Program's Purple Loosestrife Biocontrol Project  

Connecticut: Beetle Farmers Project http://www.hort.uconn.edu:80/ipm/general/biocntrl/beetlefarm/beetlfarmmain.htm

Tina Smith, University of Massachusetts Extension Donna Ellis, University of Connecticut Extension

Several greenhouse businesses received financial incentives for energy conservation and renewable energy systems this year. More funding is available and now is a good time to find out if you qualify and how to apply.

www.dsireusa.org is a comprehensive source of information on federal, state, local and utility incentive programs. The following are some incentives for CT and MA that apply to greenhouse and nursery operations.

Connecticut To help sort out what is available for Connecticut growers, John Bartok, UConn compiled a good fact sheet on Federal and Connecticut Incentives for Greenhouse Energy Conservation and Renewable Energy. It includes contacts for the USDA Rural Development Section 9006 Loan and Grant Programs for Energy Efficiency and Energy Generation, Energy Programs as part of the Connecticut Energy Efficiency fund, and many others. For details see: http://www.umass.edu/umext/floriculture/fact_sheets/UConn/08energy_resources.pdf

Massachusetts Phase 2 of the Mass Farm Energy Program (MFEP) will provide energy audits, renewable energy assessments, and/or provide incentives for implementation of audit recommendations, including those recommended by public utility programs. MFEP audits, assessments, and consultations will be paid at 75% with the applicant responsible for the remaining 25%. Incentives for implementation will be based on energy savings. Although the emphasis of Phase 2 is energy conservation and efficiency, there will be some funding opportunities for renewable energy projects, especially those projects that are not eligible for other programs. Some fundable energy saving technologies for greenhouses include: electronic temperature controls, thermal blankets, automatic or manual, sidewall/foundation wall insulation, energy efficient ventilation fans & associated tight sealing louvers, lighting, higher efficiency heating systems, higher efficiency refrigeration systems including heat recovery and IR layer of polyethylene.

See the Berkshire-Pioneer RC&D website to learn more about the MFEP Energy Audits & Incentives: http://www.berkshirepioneerrcd.org/mfep/energy.php

Berkshire-Pioneer RC&D will also offer technical assistance and grant writing assistance to at least 25 farmers interested in the 2009 funding for USDA-Rural Development's Section 9007: Rural Energy for America Program (formerly called the Renewable Energy Systems and Energy Efficiency Improvements Program).  This program pays 25% of the cost of energy projects through grants and can also provide guaranteed loans.

Contact information: Berkshire-Pioneer RC&D (grant writing, energy audits and financial incentives): Ann Gibson at 413-256-1607, agibson@berkshirepioneerrcd.org Darlene Monds, 413-256-1607, Darlene.monds@ma.usda.gov

USDA-Rural Development's Section 9007: Rural Energy for America Program (grants and loan programs for energy generation and energy efficiency) Rural Development Area Office

Tina Smith, University of Massachusetts Leanne Pundt, University of Connecticut Paul Lopes, University of Massachusetts

Rich McAvoy, University of Connecticut provided a good article on scheduling the 2009 Easter Lily crop. Below is a little information from the article. To see the entire article including energy saving options for growing Easter Lilies see: High Oil, Tough Choices - Scheduling The 2009 Easter Lily Crop. Tina Smith, University of Massachusetts

With record high energy prices lily growers will be looking for ways to reduce oil consumption or cut production costs. Tighter crop spacing, increased double cropping and lower forcing temperatures are the steps most growers resort to first. Last year some growers added an extra layer of plastic film, suspended above the truss, to provide some extra insulation. Any reduction in light, from overhead structures or baskets, will affect lily development. Every time you add an extra layer of plastic film, you reduce light transmission by as much as 10%. If the film collects condensation and dust, light transmission is further reduced, and of course more overhead baskets reduce light even more.  Easter lilies are a high light crop. The best quality lilies grow under maximum light conditions. As light is reduced, stem stretch and the incidence of lower leaf yellowing increases. If increased overhead shading is combined with tighter spacing, the incidence of stem stretch and leaf yellowing will increase even more.

In 2009 Easter falls on April 12, this is mid-date Easter that will allow plenty of time for forcing (see the 2009 Easter lily schedule (PDF) for details).  This is good news since you can grow cool for most of the schedule and still bring the crop in on time.

The normal Easter lily schedule for pot-cooled bulbs takes a total of 23 weeks. This includes 3-weeks in the pot at 60-62°F to stimulate root development, 6-weeks of bulb cooling at 40-45°F and then 14-weeks of greenhouse forcing at 60-65°F or higher as needed. For case-cooled bulbs the process is still 23 weeks but this includes 6-weeks bulb cooling at 40-45°F and then 17-weeks of greenhouse forcing.

This season start bulb programming by November 2 (23 weeks before Easter).  However, bulb programming must begin as soon as bulbs arrive and they may arrive early (24-25 weeks before Easter).

Phytophthora root and crown rot caused by P. nicotianae has been found on recently transplanted poinsettia cuttings.

The optimum conditions for disease are saturated soil and high temperatures. The pathogen does not travel easily through the air for long distances. It is possible that contaminated irrigation water can introduce the fungus to new sites but it is very difficult to detect Phytophthora in irrigation water.

Prevention is the key to managing Phytophthora because the disease is difficult to suppress with fungicides once it develops. Phytophthora like Pythium is a lower fungus favored by excess moisture and excess nitrogen fertility. Unlike Pythium, species of Phytophthora are more aggressive, more likely to be host specific.

The most likely source of origin is plant material. Start with soil-less growing media and avoid contaminating growth medium with soiled hands, tools, or flats. Promptly remove diseased plants, avoid splashing water when irrigating, and keep hose ends off the floor.

The best means for controlling Phytophthora crown rot and stem canker is with drenches of systemic fungicides which will move up into crown area such as mefenoxam (Subdue Maxx), foestyl-Al (Aliette) azoxystrobin (Heritage), zoxamide plus mancozeb (Gavel), mancozeb plus copper (ManKocide), and dimethomorph (Acrobat), Check labels for crop appropriateness. These fungicides should be rotated by chemical class to prevent resistance development.

The most effective way to halt an epidemic is to remove all affected plants. Even healthy appearing plants may be infected, so strict sanitation following an outbreak is advised.

M. Bess Dicklow and Paul Lopes, UMass Extension

The payback on energy conservation is only 6 months to 2 years according to John Bartok at a recent Connecticut Greenhouse Growers Program.

Energy conservation is an important first step even if you are considering changing to alternative fuels. So, take some time to do a walk thru energy audit of your greenhouse operation and see web sites below for links to more information on energy conservation and renewable energy to assist in your decision making and planning for the future.

For more information:

Connecticut Greenhouse Growers Program: Dealing with Energy

Fact Sheet: Greenhouse Energy Conservation ChecklistGreenhouse Energy Website

University of Massachusetts:Energy Choices for Farms and Greenhouses

North Carolina State University Database: State Incentives for Renewables and Efficiency

Leanne Pundt, University of Connecticut

Root rots, foliar diseases and under-fed plants from over-watering and tall leggy growth from low light are common problems that occur during prolonged cloudy, rainy weather.

During prolonged cloudy, rainy weather, let plants run on the dry side and spot water areas as needed to prevent over-watering. Usually plants on the edges of benches or those in the path of air movement will dry first and may need to be spot watered more often than the rest of the crop. When some plants get spot watered and are irrigated more frequently than the general crop, their fertilizer program needs to be adjusted to account for the extra leaching they receive. They may need to be "spot fertilized" as well.

If media remains wet, plants are more prone to root rot. At least once a week, randomly select plants to inspect roots to monitor the health of the crop. If roots do not look healthy, conduct a soil test for soluble salts and test roots for disease, either by sending samples to a lab or by using on-site test kits.

To prevent foliar diseases like Botryis, (see message) always water in the morning to reduce the length of time the leaves stay wet after irrigating. Avoid watering late in the day or when water will sit on leaf surfaces for long periods of time. Reduce humidity by heating and venting several times in the evening and in the morning. For details, see the factsheet, Reducing Humidity in the Greenhouse. In addition to heating and venting, use circulating fans (horizontal air flow) to continuously move the air throughout the greenhouse. These fans should be shut off when exhaust or vents are being used. Horizontal air flow will mix cool and warm air, minimizing temperature differentials and cold spots where condensation can occur on plant surfaces. For more information see: Horizontal Air Flow

If pesticides are needed, read precautions for treatments during prolonged cloudy weather. Some products such as horticulture oil may cause phytotoxicity if it remains wet on the foliage and does not dry rapidly.

High temperatures and low light conditions increase stem elongation or stretch. Water soluble plant growth regulators such as B-Nine and Cycocel are best applied during cloudy weather to maximize chemical uptake. With transplants in small containers (flats & 4" pots) materials such as B-Nine and Cycocel can be sprayed at weekly intervals. Apply the first spray as soon as new growth is evident. Use a rate at the low end of the recommended range for that species. Repeat at 7-14 day intervals as needed. For more information on using plant growth regulators see articles from March and April 2007 on Plant Growth Regulators. (Articles from search are displayed in reverse chronological order.)

Tina Smith, University of Massachusetts with input from Leanne Pundt, University of Connecticut

It is a tough time of year for greenhouse businesses to apply for energy grants, however, it may be something to think about for future opportunities if you don't have time now.

Grants and loans are available for greenhouse growers and other agricultural industries to support investments in energy-efficiency improvements and renewable energy. The USDA Rural Development Office recently announced that $220.9 million is available to agricultural producers and rural small businesses. Application deadlines are April 15 and June 16.

The Renewable Energy and Energy Efficiency loan and grant program was established to encourage agricultural businesses located in rural areas to create or install renewable energy systems and energy efficiency improvements. Grant requests must not exceed 25% of the eligible project costs. Renewable energy grants can range from $2,500 to $500,000. Energy efficiency grants can range from $1,500 to $250,000.

Eligible projects include, but are not limited to, investments in anaerobic digesters, biomass boilers and burners, solar collectors, wind energy, and energy efficiency improvements. Examples of energy efficiency projects might include the installation of more energy-efficient motors, pumps, fans, ventilation systems, insulation, curtains and heating and lighting systems.

Two separate grant competitions are available. For the first competitive window, grant-only applications must be submitted no later than April 15. For the second competitive window, grant-only applications must be submitted between April 16 and June 16. Applications for loan guarantees and loan/grant combinations must be submitted by June 16.

To qualify, you must be in a rural area and you must be either an agricultural business producing at least 50% of your gross income from the farm or a small business. For details to determine eligibility see: Eligibility Requirements

In Massachusetts, for information on applying, contact your Rural Development Area Office  Link for other states to find their USDA Service Center.

Tina Smith, University of Massachusetts

How a mix is handled can affect the air and water content of the mix. Compaction is an important factor to consider for plant root health when handling growing media. Air space that results in good drainage can be cut in half or even eliminated by compaction. To minimize compaction, containers, cell packs and plug trays should be lightly filled and the excess brushed away. The media should not be packed down, tamped down, or the filled pots tapped down on the bench several times, and the pots and trays should not be stacked directly over one another.

Another consideration is the moisture content of the mix prior filling containers. When water is added to dry components such as peat, they hydrate and swell. This swelling helps to create more aeration by preventing the particles from nesting within one another. This is especially important in plug production. Water should be added to the mix before it is placed into the container. It is best to moisten, then mix and then allowed to set overnight prior to use. If that is not possible, waiting at least a couple of hours after adding the water will help the hydration process.

How much water to add to the mix? For peat-based mixes for large containers and bedding plant cell pak production use 1 water:1 dry substrate ratio (50% moisture content). Plug mixes should have 2 water:1 dry substrate ratio (67% moisture content). The rule of thumb is, the smaller the cell, the more water to add prior to planting.

For more information see: "Greenhouse Substrates and Fertilization (PDF)", by Douglas A. Bailey, William C. Fonteno, and Paul V. Nelson Dept. of Horticultural Science, NCSU

Tina Smith, University of Massachusetts

Pre-Season Cleanup

Hopefully, your greenhouses are now thoroughly cleaned so there is no leftover debris, organic material, weeds and "pet plants" that may serve as a source of pests and diseases plus thoroughly disinfested in preparation for the upcoming growing season.

Inspecting incoming plants

Inspect incoming plants for key insects, diseases, weeds and cultural problems. Inspect the entire plant  - leaves, stems and roots for signs of pest activity and for general health. Roots should be white with vigorous growth - brown, decayed roots are evidence of root rot disease or root death due to other causes such as overwatering or high salt levels. If at all possible, do not accept plant shipments with serious insects or diseases with wide host ranges, and are difficult to treat. For example, incoming plants may be infested with resistant insects, mites or Botrytis spores that will be more difficult to treat. Do not accept plant material infected with incurable diseases, such as viruses, bacterial leaf spot diseases, or foliar nematodes. If you need confirmation, isolate a few plants showing symptoms and send them to a diagnostic laboratory. If you find isolated evidence of some insect activity, for example, aphids, and decide to keep the shipment, identify an isolated, quarantine area in which to keep the plants. Treat immediately and hold the plants in this area until you are sure that they are healthy, salable and free of pest problems. Ask workers to enter this quarantine area at the end of the day to avoid moving pest problems throughout your operation.

For more information:

Cleaning and Disinfecting the Greenhouse

IPM Scouting and Decision Making

Leanne Pundt Extension Educator University of Connecticut

There are a number of biological control agents that may be incorporated into your pest management program for western flower thrips. These include predatory mites, entomopathogenic fungi and entomopathogenic nematodes. UK researchers have developed a "Keep Down Strategy" for biological control of thrips in potted crops. The first step is to correctly identify the species of thrips (although WFT is the dominant species, other species such as onion or eastern flower thrips may be present), then anticipate (based upon past scouting records) when thrips are likely to occur. Prophylactic introductions of natural enemies start on young plants or in propagation areas.

Neoseilus cucumeris is a small, predatory mite that feeds upon young 1st instar thrips larvae. Because N. cucumeris only feeds on the young thrips larvae, it is important to start releases preventively, before thrips are detected. Apply biweekly, preventive releases to all plants. Apply N. cucumeris in bulk to flats and bench top crops. For bedding plants, apply in weeks 1-3, 5, 7 and 9. In week 2 or 3, apply nurse sachets to hanging baskets that cannot be easily reached. Check periodically for living predatory mites (N. cucumeris will be tan in color. The storage mites will be white).

Hypoaspis miles or H. aculifer are soil dwelling predatory mites that feed upon pupal stages of thrips in the soil as well as fungus gnat larvae. A single preventive release to the media at planting is generally recommended to supplement control with N. cucumeris. The predatory rove beetles, Athea, are generalist predatory beetles that feed upon thrips as well as shore flies and fungus gnats. Another species of predatory mite, Amblyseius swirskii, feeds upon both thrips and whiteflies. Researchers have noted good results in greenhouse peppers, cucumbers and some ornamental crops.

Beauveria bassiana is sold under the trade names of Botanigard®, or Mycotrol O®. It may be helpful to apply Beauveria early in the cropping cycle while plants are small (to ensure thorough coverage) and before plants flower and produce pollen, which increases thrips egg laying. Repeated applications are also often necessary.

Applications of Steinernemia feltiae (primarily used against fungus gnat larvae) also attack thrips pupae and prepupae found in the media.

For more information: Biological Control of Western Flower Thrips

Leanne Pundt Extension Educator University of Connecticut

A frequently asked question (FAQ) is "Can I use unvented heaters in the greenhouse, either for back-up or as a primary heat source?

An unvented heater is one that is designed without a flue connection so that the heat and products of combustion are exhausted into the greenhouse. Dumping these flue gases into the greenhouse may improve the overall efficiency rating as compared to a conventional heater but the pollutants and added moisture from combustion may put your plants in jeopardy.

Unvented heaters can be fired with natural gas, propane or kerosene. These fuels are advertised as clean-burning. This is generally true if the burner is clean and has been adjusted to top efficiency. A heater that has been serviced in the fall will probably not be at peak efficiency as spring approaches. Inefficient combustion can emit unwanted and harmful pollutants into the greenhouse that can affect the plants and the people working with them.

Care should taken if you install unvented heaters. Be sure to have an adequate makeup air supply and provide frequent maintenance. Use indicator plants near heaters or commercially available indicator tubes to warn of excess levels of pollutants.

For more information about the fuels, the combustion process and their pollutants see the fact sheet:

Problems With Using Unvented Greenhouse Heaters

John Bartok, Extension Professor Emeritus, UConn

Many growers are performing their own soil tests for pH and soluble salts on-site. Others are sending samples to different labs for their soil tests and some do a little of both. Often growers end up with a confusing collection of tests done different ways with widely different "numbers".

There are three commonly used methods of testing soilless media based on the use of water as an extracting solution. They are: saturated media extract, 1:2 dilution method, and leachate pourthru. The number representing the level of soluble salts from a soil test using a 1:2 dilution method are going to mean something different than results from saturated media extract (SME) or leachate pourthru. For example, 2.6 would be "extreme" (too high) for the 1:2 method, "normal" for SME, and "low" for leachate pourthru. Always use the interpretative data for the specific soil testing method used or otherwise you could make an incorrect interpretation of the results. The differences in pH results between the tests is much smaller.

The major difference between the current methods of greenhouse media testing is the way plant-available nutrients and soluble salts are "extracted" from the media samples for analysis. Differences between the actual methods of pH, soluble salts, and nutrient analysis and the laboratory equipment used to do the analyses are not as important as how the plant-available nutrients are extracted from the sample.

When people think of "soil testing", they might imagine some procedure which analyses the solids in a mix for pH, nutrients, and soluble salts. However soil samples themselves are not actually analyzed during a soil test, but rather plant-available nutrients are pulled out or "extracted" from the sample using an "extracting solution".

For more information on the three different methods for testing soil , proper sampling and a comparison table with soluable salt levels for each of the methods, see the fact sheet:

Current Methods of Greenhouse Media Soil Testing and How They Differ

Tina Smith

Sometimes poinsettias are prone to lateral stem breakage and some varieties such as Freedom may be more susceptible to this problem. The crop may look healthy and the roots look good, yet an occasional branch will wilt for no apparent reason. There are several possible causes of this condition.

• Too many nodes were left on the poinsettias during the pinch. Lower branches on these plants may be shaded and grow in a more horizontal position putting pressure on the junction of the branch and the main stem.
• Not enough calcium was used in the fertilizer program resulting in weak shoots.
• Poinsettias were pinched too early resulting in side branches growing too long.
• Low light levels during the vegetative growth phase after the pinch causing weak lateral branches.
• Lack of care when hand watering can cause a small physical break at the junction of the branch and main stem that is not observed until the branch wilts. The branch feels like a "loose tooth", still attached, but the vascular system is broken.

Although this condition usually occurs late in the production cycle or during shipping, it can occur at any time. Once the branch is wilted, it will not recover. It will have to be gently removed.

Photos: Lateral stem breakage, 2

Tina Smith and Douglas Cox, University of Massachusetts

Plant trials are important tools. Pack trials provide you with a snapshot of how new plants perform in the greenhouse. That's valuable information for your production process. Field trials, on the other hand, offer a view of how plants perform in the field. That's valuable information too, because it provides an assessment of how your customers see plants.

You might decide to produce a new plant because the catalog photos or pack trial plantings are spectacular, it seems to fill a gap in your product list, and the production protocol fits your facility. But, if that plant doesn't perform well in your customers' gardens, then your customers might go elsewhere next year - to a place where they know that the beautiful plants they buy will look terrific not just on the day of purchase, but also fifteen weeks later in their gardens.

We began field trials of new annual flowers at the University of Maine in 1988. Each year, we obtain seeds or cuttings of new plants, grow them to retail size in the greenhouse, bed them out the first week of June, and maintain them through the season. Our field maintenance includes planting, mulching, irrigating when needed, weeding and periodic fertilizing. This year, our field season had a terrific start: good soil moisture, perfect planting conditions in early June, and good rain for the month of June. July brought warm days and cool nights, which made some plants stall. Our recent hot, humid weather has caused some stress (the ratings below were done just a few days into this high heat and humidity).

We have 93 plants in the 2007 field trials. Our first ratings were done on July 20, about midseason. Here are ten plants that look terrific as of midseason:

Basil 'Pesto Perpetuo' (vegetative; Proven Selections) This basil produces blue-green leaves with white margin, very tight and prolific branching and an upright habit. To top it off, I haven't seen any flowering yet. For either mixed containers or patio herb pots, this plant provides fragrance and form.

Dahlia 'Mystic Illusion' (vegetative; Proven Winners) At the time I rated the plants, this hadn't flowered yet (it has since produced a few lemon yellow flowers). I was smitten by the shiny purple-black foliage, and neat and uniform habit of the plant.

Juncus pallidus 'Javelin' (seed; PanAmerican Seed Co) Like javelins, the leaves of this rush point upward, reaching a height of about 18". They're a good textural foil for more colorful annuals, and have not shown any evidence of disease or pest problems.

Lobelia 'Waterfall Light Lavender' (vegetative; Ball FloraPlant) Lobelia often has great color in spring, but looks distressed by midsummer. In recent years, several lobelias have performed much better. 'Waterfall Light Lavender' is one of these – its stems trail outward and reached a spread of about 20" by late July. It continues to set new flower buds.

Marigold (African) 'Vanilla' (seed; PanAmerican Seed Co) 'Vanilla' has the lush dark green foliage and uniform vase-shape habit of many tall marigolds. Plants are topped by 3-4" cream-colored flowers.

Petunia 'Supertunia Raspberry Blast' (vegetative; Proven Winners) This bold petunia received considerable attention at this spring's pack trials, and it continues to be a favorite in the field. The hot pink broad star center with darker edge may not be for everyone, but in the right mixed container it would be stunning.

Petunia 'Shock Wave' (Ivory, Pink Vein, Purple, Rose) (seed; PanAmerican Seed Co) This series has performed very well (as of midsummer, 'Ivory' is my favorite for both color and floriferousness), and is intermediate in both plant spread and flower size between the small calibrachoas and the larger spreading petunias. This would be perfect in a smaller mixed basket, in which larger petunias become overwhelming by summer's end.

Sedum 'Lemonball' (vegetative; Proven Winners) 'Lemonball' is a dependable, high quality plant with green-yellow foliage. Its spreading mounded habit is both neat and vigorous. It has not flopped apart in the center, nor has it flowered to date. Its drought tolerance makes it perfect for small terra cotta containers.

Stipa lessingiana 'Capriccio' (seed; PanAmerican Seed Co) 'Capriccio' is a cultivar of "Siberian Steppe Grass"; that's a hint that it's probably hardy here in New England. The clumps of leaves reach about 16" in height, and are more finely textured than fescues - the leaves sway gently in the slightest breeze.

Zinnia 'Profusion Knee High Red' and 'Profusion Knee High White' (seed; Ball Seed Co) I've been a big fan of the 'Profusion' series, and the new Knee High additions to the series look great. Both the red and white flowered types are uniform, and a bit taller (20") and more open than the standard 'Profusion' zinnias.

We'll rate the plants again at the end of August; if you'd like a copy of the trial summary, just send me an email request: LSTACK@umext.maine.edu

Photos of plants as of July rating: Marigold 'Vanilla', and Sedum 'Lemonball'

Lois Berg Stack, University of Maine

Growers are cautioned that cold night temperatures are expected this week in most areas. Watch weather reports for your area and plan to cover susceptible plant material growing outdoors.

Some growers are moving cool tolerant plants outdoors earlier in the season to utilize outdoor growing space during early spring and free up space in greenhouses. Safely moving plants outdoors is going to depend on the cold tolerance of the plants, where you are located and how well plants are hardened off. Even perennials, if grown in a greenhouse and not hardened off properly will be injured by frost.

Some cold tolerant plant material includes perennials and selected annuals such as Pansy, Alyssum, Snapdragon, Phlox "Intensia" series, Osteospermum, Nemesia, Calibrachoa, Verbena, Diascia, "Supertunia" series, Bidens and Dianthus. Pleasant View Gardens, Loudon, New Hampshire reports that they have had annual plant material growing outside for about a week and a half without problems so far this year.

Here are some guidelines from Pleasant View Gardens' "Cool Tolerant Annual Program":

• Get vegetative growth to desired size before cooling down plants (plants grow very slow under 50°F)
• Run greenhouse cool (45-55°F) for 1 week to harden off plant material before moving outdoors.
• Keep an eye on the weather forecast - don't move plants outdoors if a hard frost is predicted colder than 28°F) at any point within 3 nights of when plants would go outside. If weather is to be mild move plants outdoors.
• Cold frames work great (non heated but covered)
• Avoid low-lying areas as frost settles in these areas.
• Cover with Remay type product (5 mil thickness) to protect when needed. If temperatures go below 28°F, heavier cover may be needed.
• Water in the morning, then let plants dry down and go dry into the night.
• If frost does occur, overhead irrigate in the AM before the sun hits the plants.
• Good plant spacing is critical for air movement.
• During rainy periods, watch for both botrytis and nutrient leaching. It is important to be able to fertilize plants. Also, flowering is delayed by colder average daily temperature.

Keep in mind that you are always taking a chance when growing outdoors in early spring and occasionally plants will get damaged. By choosing cool tolerant plants, hardening-off plants, watching weather forecasts and providing extra protection when needed, you will minimize the risk, grow higher quality plants while providing extra growing space.

Note that plant selection and hardening off plants is also good advice for retail customers.

Tina Smith

As plant material is received and handled during this busy time, here are a few guidelines to have greater successes and fewer problems.

Open and unpack the boxes immediately upon arrival and check the physical condition of the plants. Also inspect plants for root and foliar diseases and for insects and mites. Report any damage or discrepancies immediately to your supplier (most companies want to hear within 24 hours).

Place plant trays on benches and water thoroughly with plain water (no fertilizer); be sure that plugs on the edges of the trays are thoroughly watered. Plugs can dry out quickly due to the small volume of growing medium; check the trays 2 or 3 times daily for watering. After the initial watering, apply a general-purpose fertilizer (such as 20-10-20) at 50 to 60 ppm of nitrogen at every other watering. Allow plants to acclimate to the greenhouse conditions for 24 to 48 hours before transplanting.

Water the plug trays thoroughly 2 to 3 hours before transplanting; this aids in removing the plugs from the trays. Prepare your cell packs, pots or hanging baskets by filling them with pre-moistened growing medium and pre-dibbled holes for the plugs. Lightly fill containers and brush off excess. To prevent compaction, do not pack down or stack ( "nest" ) filled flats.

Take special care during transplanting to handle plants gently and avoid planting too deep. Stems of tender cuttings and seedlings can be easily injured when grasped or "pinched" too tight. This can lead to stem cankers causing plants to wilt and die. Plant plugs and rooted cuttings at the same depth as the original plug. Some transplants may have elongated stems and it is tempting to "bury" the stem. Resist the temptation, except for plants that you have experienced are adaptable such as tomato plants.

Rooted cuttings from different wholesale suppliers may contain a variety of growing media. Adjust watering habits accordingly.

Tina Smith

The accuracy of a disease diagnosis can only be as good as the sample provided. To provide a good sample, be sure that the sample contains the right part of the plant. Symptoms may appear in parts of the plant that are not infected with the pathogen. For this reason, if possible, submit as much of the plant as possible. Ideally, this would be an intact plant.

Secondly, the samples must be fresh and in good condition. “Dead plants tell no tales.� Due to secondary infections in extremely decayed plants, it is difficult to determine which organism may have created the problem in the first place. If possible, send in several plants with a range of symptoms from moderate to severe.

Keep leaves dry and free of soil. Wet samples with soil on the leaves promote the growth of secondary pathogens and create problems that did not exist when the sample was originally collected. Don’t ever add water to your sample.

Complete the required form to be sent with the sample or make sure to include detailed information including: host plant, date collected, plant history (planting date, approximate age, cultural practices), when symptoms occurred, description of the problem, pesticide treatments, and your contact information. Keep accompanying paperwork separate and do not include in the bags with the sample. Ideally, paperwork could be placed in its own Ziploc bag.

Rapid delivery may be critical to an accurate diagnosis. Samples that take a long time to get to the diagnostic lab have a greater chance of decaying or drying up making diagnosis difficult. If you are close enough to a lab, you may want to hand deliver the sample. If you are too far from the lab ship the sample overnight. Many labs are closed over the weekend and you may not want to ship the sample of a Friday or during a holiday. Call your diagnostic lab prior to shipping to make sure that they will have someone there receive the package.

Leaf spots and blights Select leaves which show a range of symptom development. Place leaves between paper towels or sheets of paper to keep leaves dry. Place the package in a plastic bag, and then into the envelope for mailing. Never wrap leaves in wet paper towels.

Stem Cankers When a canker occurs on a large plant, cut a section of the stem with the symptoms, wrap in newspaper and place in a plastic bag for mailing. If the plants are small (1 foot or less), shake the soil from the roots, wrap in newspaper and put into a plastic bag for mailing.

Wilt, Crown Rot or Root Rot If the plants are 1 foot or less, include the entire plant. Include the root system with the plant, leaving the growing media on the roots. Place the root ball into a plastic bag and tie off at the crown to keep the media off the foliage. If the plants are large, send a portion of the plant that includes the infected tissue. For wilt diseases, include the lower stem tissue and roots.

Poor growth, Defoliation, Scorch These symptoms are usually caused by nutritional or environmental factors. They may also be the result of root rot or vascular disease. Collect a specimen as for “Wilt� (above); be sure to submit a soil sample to a soil test laboratory.

For a list of Disease Diagnostic Laboratories see the message posted February 15, 2007.Bess Dicklow, University of Massachusetts Plant Diagnostic Lab

Tina Smith, University of Massachusetts

Prevention and correct identification of insect, diseases and nutritional problems can help you save money by reducing crop losses, improve the quality and marketability of your crops and prevent the application of the "incorrect" pesticide or fertilizer.

Here is a listing of the laboratories in Massachusetts, Connecticut and Rhode Island.

Massachusetts University of Massachusetts, Amherst Soil and Plant Tissue Testing Laboratory http://www.umass.edu/plsoils/soiltest

University of Massachustts, Amherst Extension Plant Diagnostic Laboratory http://www.umass.edu/agland/diagnostics/

Connecticut University of Connecticut Soil Nutrient Analysis Laboratory http://www.soiltest.uconn.edu Disease Diagnostics, Soil Testing Connecticut Agricultural Experiment Station http://www.caes.state.ct.us

Rhode Island University of Rhode Island Plant Clinic Phone: 1-401-874-2750

Growers may also consider purchasing on site disease testing kits. There are currently three companies that manufacture test kits available for on-site testing. Not every company carries kits for all diseases. Note: Kits need to be refrigerated and expiration dates observed.

ImmunoStrips from Agdia Inc. http:www.agdia.com, Phone 1-800-622-4342

AgroCheck Kits from Hydros Inc www.hydros.cc/ Phone 508-540-2229

Alert Kits from Neogen Company, http://www.neogeneurope.com/

For more information see the fact sheet "Diagnostic Test Kits"

Tina Smith and Paul Lopes, University of Massachusetts Leanne Pundt, University of Connecticut Heather Faubert, University of Rhode Island

Greenhouse sanitation and disinfecting are steps that growers can take now to prepare for the spring growing season. Clean as early as possible to eliminate over-wintering sites for pests to reduce their populations prior to the growing season. Greenhouse pests will over-winter in weeds and protected areas in unheated greenhouses and especially this year with unseasonably warm temperatures. Remember that pests are much easier to prevent than to cure.

Begin by thoroughly cleaning the floor of soil, organic matter and weeds. Pay particular attention to areas around furnaces or along side walls where small weeds may exist. Install physical weed mat barriers if floors are bare dirt or gravel and repair existing ones. Weed barriers not only prevent weeds, but also make it easier to manage algae. Avoid using stone on top of the weed mat that will trap soil and moisture, creating an ideal environment for weeds, diseases, insects and algae.

Benches, preferably made of wire, should be disinfected and pots, flats and trays should be either new or disinfected. Bench tops and work tables should be made of a non-porous surface such as a laminate that can be easily disinfected. Avoid using bare wood for these tasks. Keep hose ends off the floor and growing media in a clean area and covered. Avoid holding plant material and accumulating contaminated pots, media or debris in the media mixing area.

Next, disinfect the growing and plant handling areas, and irrigation system. There are several different types of disinfectants that are currently used in the greenhouse for plant pathogen and algae control. They are quaternary ammonium compounds (Green-Shield®, Physan 20®, and Triathlon®), hydrogen dioxide (ZeroTol®, Oxidate®) and chlorine dioxide (Selectrocide). All these products have different properties, so read and follow label directions. Chlorine bleach may be used for pots or flats, but is not approved for application to walls, benches or flooring. Alcohol is flammable and therefore not used as a general disinfectant. However, it is useful as a dip or swipe treatment to disinfect propagation tools. If possible, disinfectants should be used on a routine basis both as part of a pre-crop clean-up program and during the cropping cycle.

Organic growers have limited options for disinfectants. Oxidate® is the only material mentioned above that is currently listed by the Organic Material Review Institutes (OMRI), see www.omri.org. Ethyl or isopropyl alcohol is also allowed under the organic standards. Organic growers should always check with their certifying organization before using any material new to their farming practices.

Finally, pest population will be reduced significantly with a fallow period of four weeks, but having an empty greenhouse for even two weeks can help. Before placing plants in a greenhouse this winter, place yellow sticky cards throughout the greenhouse and on the floor after watering benches and the floor to detect over-wintered thrips (emerging from pupae), fungus gnats, whiteflies or other insects, Close up the greenhouse and turn on the heat to break dormancy. Observe cards after two days. Also place a few sticky traps on the outside perimeter of the greenhouse, especially under vents to detect pests. Check weeds around the greenhouse perimeter for aphids. When weather permits, use horticultural oil on weeds outside, around the greenhouse perimeter to smother over-wintered pests such as aphids.

To learn more about cleaning and disinfecting see the fact sheet: Cleaning and Disinfecting the Greenhouse

Tina Smith, University of Massachusetts Organic information provided by Vern Grubinger, University of Vermont

Growers have expressed interest in growing herbs organically. The US Department of Agriculture has developed a set of standards that food and plants labeled "organic" must meet. To become organically certified, a government approved certifer inspects the farm to make sure the farmer is following all the rules necessary to meet USDA organic standards. The USDA National Organic Program web site provides a listing of certifying agencies.

Here are a few general guidelines to consider:

• Use organic seed or if organic seed is not available, untreated seed.

• Use approved materials  - i.e. potting soil, fertilizer and pest and disease control substances.

Herbs are light feeders compared to traditional bedding plants. Lower rates of 100- 150 ppm constant liquid feed are preferred. In addition, routine clear watering is helpful to leach excess salts from the media, especially as herbs prefer to be kept on the dry side. Over fertilizing herbs results in lush growth that is more prone to foliar diseases such as Botrytis blight and web blight, and makes the plants more attractive to sucking insects. Excess levels can result in root tip damage.

If using organic fertilizers, no more than 50% of the nitrogen should be in the ammonium form. As with any fertilizer, your choice should be based upon the pH and alkalinity of the greenhouse irrigation water as well as the pH and nutrient supplying ability of the potting soil.

The Organic Materials Review Institute (www.ormi.org) is a non-profit organization that specializes in the review of pesticides and fertilizers for use in organic production. See their web site for a listing of approved insecticides and fungicides. (Some products may be regulated and subject to restrictions.)

For a listing of selected insecticides and fungicides labeled for use on herb bedding plants, (updated in 12/06), go to the UConn IPM Web site and see the tables listed for the Publication, Pest Management for Herb Bedding Plants Grown in the Greenhouse.

If you are also growing crops conventionally,

• Keep production areas separate and plan on keeping good records to document this separation.

•  Plants must not be contaminated or commingled with non-organic plants or prohibited substances.

Additional sites for information on organics, include: Northeast Organic Farming Association Sustainable Agriculture Research and Education Northeast Organic Network

There are also a number of fact sheets and publications on growing herbs organically from the National Sustainable Agriculture Information Service.

Leanne Pundt University of Connecticut

While many insecticides kill pests by contact activity, some insecticides have either systemic or translaminar properties. A good article on the subject was written several years ago by Dr. Raymond Cloyd, now at Kansas State Univ. and I thought the information might be useful.

Systemic insecticides are pesticides in which the active ingredient is primarily taken up by plant roots and transported throughout the plant, such as the growing points where it can affect plant-feeding pests. Systemics move within the vascular tissues, either through the xylem (water-conducting tissue) or phloem (food-conducting tissue) depending on the characteristics of the material. The water solubility of systemic insecticides determines their movement within plants. Very water soluble materials are readily taken up by plant roots or leaves. Systemic insecticides are most effective on insects with piercing- sucking mouthparts, such as aphids, whiteflies, mealybugs and soft scales because these insects feed within the vascular system. Most of the systemic insecticides have minimal activity on spider mites because spider mites remove chlorophyll and don’t feed within the vascular tissues. Systemic insecticides should be applied when plants have an extensive, well-established root system and when they are actively growing.

Translaminar insecticides penetrate leaf tissues and form a reservoir of active ingredient within the leaf. This provides residual activity against certain foliar-feeding insects and mites. Because the active ingredient can move through leaves, thorough spray coverage is less critical to control spider mites, which normally feed on leaf undersides. Insecticides/miticides with translaminar properties include but not limited to abamectin (Avid), pyriproxyfen (Distance), chlorfenapyr (Pylon) and spinosad (Conserve). In general, these types of materials are active against spider mites and/or leafminers.

For more information, read Dr. Cloyd's complete article: Systemic, Local Systemic, or Translaminar: What's the Difference?

Tina Smith

May is the busiest time of year. It can be difficult to answer all of your customer's gardening questions, but providing this customer service, and distinguishing your garden center as a source of knowledgeable staff is important. Here are some resources that may help you to answer your customer's gardening questions.

In Connecticut University of Connecticut Home and Garden Education Center Toll free phone 1-877-486-6271 Web Address: www.ladybug.uconn.edu

The Connecticut Agricultural Experiment Station Phone: New Haven: 203-974-8500 Valley Laboratory: 860-683-4977 Web Address: www.caes.state.ct.us

In Rhode Island University of Rhode Island Cooperative Extension Education Center Phone 401-874-2900

URI Gardening and Food Safety Hotline Mon- Thur 9 am - 2pm, 1-800-448-1011 Web Address: www.uri.edu/cels/ceoc

In Massachusetts Link to: Master Gardener Hotlines, Botanic Gardens, Poison Control Centers, Conservation and Wildlife Information University of Massachusetts Extension Agriculture and Landscape Programs

The following websites may also be helpful: UConn Plant Database University of Connecticut IPM Gardening Resources - Cornell University Perry's Perennial Pages Ohio State Plant Facts Plant Pest Handbook

Leanne Pundt and Tina Smith

Revised information concerning the Worker Protection Standard online!

As of September 2005 a revised edition of the EPA How to Comply With the Worker Protection Standard for Agricultural Pesticides:  What Employers Need to Know is available online.

Take a minute to review the site and consider book-marking the web site for future reference.

The following link will get you access to the document: http://www.epa.gov/agriculture/htc.html

Paul Lopes