Q. Generally, how can I control pest, disease, and environmental problems in my garden?
In general you have less time to make a control decision on seedlings, transplants, and newly planted trees and shrubs. Many pests and diseases do not need to be controlled on older or mature plants. For environmental problems, the site and/or cultural conditions may need to be modified to correct the problem.
Realistic thresholds should be set for insects and diseases. Pest or disease progression should be monitored carefully. It is very important to identify the pest or disease and become familiar with its life cycle. Some pests and diseases may not require control, while others may. For example, gypsy moth should be controlled, because oaks suffer from early defoliation, and use up energy reserves to produce more foliage. Eastern tent caterpillar occurs early enough in the season for cherry trees to re-foliate without causing harm to the tree. Often by the time disease or insect damage is observed, it is too late to do anything about the problem until next season.
Treatment decisions depend on the type of plant that has a problem. If a plant is easy to replace such as an annual, just pull the problem plant and replace it. To prevent buying problem plants, always check them thoroughly, by looking at the foliage, if discoloration and growing poorly, move to the next plant. Plants that continue to grow throughout the season will often outgrow the pest or disease damage, as long as they are growing in their favorable environment.
Once you have identified the problem and determine that it requires corrective action, select a control strategy. Always select the least toxic solutions first such as physical (hand removal, change watering practices, pruning out damage, etc.) and biological (encourage beneficial by planting a diversity of plants in your garden). Pesticides should be used selectively (spot treatments) with the least toxic materials ( B.t., insecticidal soaps, horticultural oils, etc.) used first.
Continue to monitor the plant’s health after treating a problem to determine if further action is needed. A healthy plant can deter many problems.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service