Growing Green: Pest management practices for vegetable garden
BY DIANE DORN
Special to The Press
Even though the vegetable garden is in full swing, there is always more to do. Pests and weeds are now a common culprit.
Pest management programs for garden vegetable should first focus on nonchemical or cultural methods.
Resistant cultivars, proper cultural practices and sanitation are important in an effective pest management program.
Cultural strategies are numerous, depending on the target pest, and include the following:
- Selecting good sites.
- Select cultivars with resistance or tolerance to target pests.
- Maintain healthy and vigorous plants with good nutrient and moisture management.
- Do not over-fertilize, especially with nitrogen.
- Promote good air circulation within the garden to promote drying of the plants.
- Use good sanitation practices for tools and equipment.
- Use plant rotations to avoid the buildup of pests.
- Create habitats for beneficial insects.
- For hand and mechanical weeding, use organic (for example, straw or bark chips) or inorganic (for example, plastic) mulches.
- Use drip irrigation or watering at the base of the plants to minimize leaf wetness.
- Work in the garden when the plants are dry.
Diseases or insects may cause a serious reduction in the vigor, quality and productivity of plants.
The success or failure of a fungicide or an insecticide is related to correct identification of the pest problem; selection of the appropriate pesticide; the method, rate, and timing of application, and weather conditions at the time of application.
Always follow directions on the container or package when mixing and applying pesticides. Never increase the amount of pesticide or decrease the amount of water you mix with the pesticide.
What about weed management?
Dense weeds not only rob vegetables of moisture, light and nutrients, but can also harbor insects and create an ideal environment for disease-causing organisms.
Eliminate young weed seedlings with shallow hoeing or cultivating. Never allow weeds to set seed.
Place organic mulches such as straw (four to six inches deep), newspaper or cardboard around plants and between rows to reduce weeds and conserve moisture.
Apply organic mulches only after the soil is warm (normally about June 10) because they decrease soil temperatures and, therefore, can increase frost severity. If using newspaper or cardboard, it is strongly recommended to wet it thoroughly after applying it to the soil.
Additionally, consider placing compost or compound manure on top of the newspaper or cardboard to promote their degradation and prevent temporary nitrogen tie-up. Manage perennial weeds year-round near and in plantings as they can harbor disease-causing organisms.
To help keep weeds and weed seeds out of plantings during the fall and winter months, consider sowing a cover crop in late summer or fall (for example, annual ryegrass or spring oats mixed with hairy vetch). Turn the cover crop into the soil about one month before spring planting.
As a general rule, avoid using herbicides for weed management in small planting areas for several reasons. First, no herbicide that can be safely used on all kinds of vegetables is available. Second, herbicides are difficult to apply at proper rates in small areas with hand sprayers.
In most cases, some areas will receive too little herbicide for effective weed management and other areas may receive such heavy rates that the vegetable plants will be damaged or killed. Also, you risk damaging or killing your plants from spray drift.
“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613.