Garden Pests: Identify, Prevent, Control

By George Graine, Fairfax Master Gardener
“Earth is here so kind, that just tickle her with a hoe and she laughs with a harvest.”
— Douglas Jerrold in “A Land of Plenty” (1859)
There is a trend toward biological, natural and organic formulations for pest control. This trend is likely to continue as the industry produces more effective products. In the meantime, a new book, “The Vegetable Garden Pest Handbook: Identify and Solve Common Pest Problems on Edible Plants” by Susan Mulvihill (Cool Springs Press, 2021) will be of significant assistance to help you as a vegetable gardener. Assuming you desire to garden without the use of chemical pesticides, this book will make perfectly good sense. We know there are a multitude of pests that tend to frustrate our ability to garden successfully; therefore, you need to know and understand what is happening in your vegetable garden. This book will go a long way toward enabling you to cope with real and potential problems. The foundation for “fighting” pest problems is to secure the survival and ability of plants to thrive. Your problem, really your challenge, is to know how to keep pests from sharing your bounty. According to Mulvihill, the focus of this book “. . . is on natural, low-impact (to the environment, not the pests) controls for pests that become problematic.” This book will help, although not guarantee, a decent vegetable harvest for your efforts.

Starting with the basics, why garden organically? At its simplest, this means gardening without the use of chemicals which include pesticides, other killing “cides” and even quick fix synthetic fertilizers. The reason for gardening without these products is really quite simple. In addition to your personal safety, there is also the possibility of killing non-target plants and insects. This can happen due to over-spray of a chemical that could volatilize when the temperature exceeds 80 degrees F or when it is a windy day. Unfortunately this can happen without your knowledge. Then days later you may find some damage to your plants. In other words, you do not need chemicals in order to produce healthy plants. This applies to plants in other parts in your landscape as well.

Mulvihill says the concept of Integrated Pest Management, IPM for short, is a “systematic approach of choosing the most environmentally friendly method of handling pest problems.” Executing your own IPM program requires a variety of steps and/or considerations. None of these are difficult! First of all, you need to identify the pest. Is it a harmful insect or is it one of the good guys? A good guy is defined as a bug that feeds on another bug because it is a source of food. As an example, lady bugs and especially their larvae (good bugs) gorge themselves on aphids (bad bugs). Before proceeding with additional benefits of gardening the organic way, there may still be a need for a synthetic product (chemical) in some situations. The reason for this is due to the fact that some organic products may not be effective. This may happen because some organic products are more UV sensitive. Note that regardless of whatever type product you apply, the label on the bottle, bag or spray is the law. It is important that you read and heed the application rate and instructions regardless of the degree of infestation. As noted above, it is important to be aware of the temperature and wind conditions before you take action to control a pest problem.

Good cultural practices will go a long way toward achieving healthy thriving plants. Often this means choosing the appropriate location for sun or shade-tolerant varieties. It is also necessary to understand other environmental growing conditions such as your area’s average frost dates, meaning when you can expect an early or late frost. Assuming you are not growing vegetables hydroponically (in water), then it is also critical to understand your soil in terms of pH and available nutrients. For a greater understanding of soil, have it tested by a soils laboratory such as our very own soil lab at Virginia Tech. Free soil sampling kits are available at most public libraries, and the cost of the test is $10. Note that growing vegetables is often not the same as growing a lawn, shrub or tree. In order to know your soil for these plants, a separate test is necessary. The reason for a soil test is to determine the adequacy or need for supplemental nutrients, i.e., is the soil OK or does it have a deficiency for any chemical element?

Other considerations include “proper” watering. Just a spritz when the spirit moves you will not help to produce a vigorous vegetable garden. Also, consider selecting disease and/or pest resistant vegetable varieties. To know this in advance of planting could be based on your prior experience or what you may have heard from others who grow vegetables. Practicing crop rotation will help to prevent or reduce vegetable pest problems. Since you will probably have open space in order for plants to have room to grow, know that in advance weeds are very opportunistic. That is another problem outside the scope of this article. Surely there has been a lot of positive publicity on how to attract pollinators to your garden. Attracting birds with a feeder is also beneficial because they will devour pests.

The “Meet the Bugs” section is the heart of the book. Here you will find many charts that include plant name, plant family, problems/damage, and possible culprit. After you determine the vegetable you plan to grow, next check the plant profile. At this point you will find the details on each pest including life cycle, signs of activity, controls and more. In addition, a color photo and general information about each pest is clearly indicated.

In summary, “The Vegetable Garden Pest Handbook” is a valuable and comprehensive resource. Refer to it often because you will learn not only how to identify pests but also how to control and even prevent them in the first place.