Growing Herbs Organically
Tuesday, 02 January 2007 10:19
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
