It depends on the crop that you grow, the growing season, and the level of crop damage that you are willing to accept. Some crops such as okra and beets just don't have many disease or insect problems and are much easier to grow without pesticides. If the growing season is a wet one, there is going to be more disease pressure. Although they may take a little more time and effort, you can use the following methods to help avoid the use of chemicals:
• Before Planting
- Select a site that is sunny and well drained.
- Remove or turn under old crop debris well before planting.
- Select disease-resistant seed varieties.
- Purchase disease-free transplants.
- Avoid areas with poor air movement.
• Planting Time
- Consider seed commercially treated with fungicides.
- Plant seed into warm soil well after the danger of frost is past.
- Space plants to assure air movement between them.
- Use proper fertility.
- Use raised beds to improve drainage.
- Avoid overlapping plantings to keep diseases from moving from the old crop to the new one.
• During the Growing Season
- Regularly inspect plants for disease.
- Remove and destroy badly diseased plants.
- Control weeds which harbor insects and disease organisms in and near the garden. These weeds include pokeweed, plantain, Johnson grass, milkweed, wild cucumber, nightshade, ground cherry, and clovers.
- Control insects which feed on vegetable plants or spread disease organisms.
- Water and mulch to avoid unnecessary plant stress.
- Avoid wetting foliage, or irrigate early in the day so foliage can dry before dark.
- Use labeled fungicides for control only when needed.
- Avoid working the vegetable garden when leaves are wet to reduce the spread of bacteria.
- Encourage air movement by thinning plants or pruning away excess growth.
- Encourage natural enemies (predators and parasites) of insect pests by providing food and/or shelter that enhances their survival. For example, certain flowering plants produce nectar that is fed upon by natural enemies; these "insectary plants" can be incorporated into the garden, but be aware that some pest insects may also find these plants attractive.
If the use of chemicals becomes absolutely necessary to produce a successful crop, contact your local Cooperative Extension office for specific recommendations.
