Integrated Pest Management (IPM) is a term that’s been added to many gardeners’ vocabulary over the past few years. But exactly what is IPM? Many people think it means you purchase “good” insects, like ladybugs, and release them in your garden. Many also think that by doing this, they won’t need to spray anymore. Well, that’s not exactly true…

Scouting for pests

Carefully inspect a plant for any pests before buying it. This means checking the roots, too!

Photo Credit: ©2002 Buglady Consulting

Coleomegilla maculata

Native to the US, Coleomegilla maculata (pink spot ladybird beetle) is an excellent predator.

Photo Credit: ©2005 Buglady Consulting

Garden bio diversity

Use different plants in your garden to attract beneficial insects. I grow sunflowers, which attract many “good guys,” next to my tomatoes. (And yes, I’m holding beets.)

Photo Credit: ©2002 Buglady Consulting

IPM is the practice of long-term prevention and suppression of pests. Several methods are commonly used, including inspecting plants for pests, growing pest-resistant plant varieties and implementing good cultural practices in the garden. When enforcing IPM, pesticides are only used as a last resort when pest levels reach a level that you’re uncomfortable with. And if you do decide to treat with a pesticide, spray products that are considered “soft,” such as horticultural soaps and oils, are used.

One of the key components of IPM is scouting – inspecting plants for pests. (It’s helpful to carry a magnifying lens or loupe with you.) You’re probably already scouting and don’t even realize it: It’s basically looking around the garden and making observations. If you want to take an extra step, you can keep a notebook and write down what you see. (It’s important to keep dates along with your observations.) By keeping notes, you’ll eventually start to see patterns and learn when to start looking for particular pests before they attack.

Preventing the Problems

It’s well-known that when a plant is grown in optimal conditions, it’s less likely to have insect and disease problems. But why? (Because everyone says so, right?)

Let’s look at an example: Meet Amy. She likes to garden and loves roses. While at the local garden center, Amy finds two rosebushes that she must have for opposite sides of her driveway. She wisely inspects the plants for any apparent pest and disease problems. After determining that they’re clean, she goes ahead with her purchase.

After Amy plants her rosebushes, she realizes that one is now located in full sun and the other’s in full shade. The rose in full sun is receiving enough light and can therefore properly photosynthesize, in turn producing enough food and allelochemicals for the plant to stay healthy. “What are allelochemicals,” you ask? They’re compounds produced naturally by a plant, functioning primarily to protect it from natural enemies. In other words, they’re “built in pesticides.” (These chemicals are now extracted from certain plants to be used as pesticides. A good example would be pyrethrin insecticides, which are made from chrysanthemum flowers.)

Now back to the rosebush placed in the shade on the other side of Amy’s driveway. That plant has a problem: There’s not enough light for it to photosynthesize, preventing food production. This will, in turn, lead to an insufficient production of allelochemicals. This lack of light is called a stress factor.

Two things can cause stress factors: a lack of natural resources or an inability to use those resources. A plant’s natural resources are primarily light, water, temperature and nutrients. If a plant is inhibited from getting any of these necessities, it can be in trouble, leaving it open to insect and disease problems. Giving your plants the proper growing requirements it needs is a good way to avoid stress factors. Selecting plant cultivars or varieties that are resistant to problems will also give you a head start against stress.

And when it comes to plant maintenance, keep this in mind: More is not better. It’s so tempting when watering or fertilizing a plant to “add a little extra.” If your thinking is, “This will help the plant have better health,” think again! Too much fertilizer might push the plants to grow too fast or can even become toxic to the plant. Growing too fast may also cause a decrease in the concentration of a plant’s allelochemicals.

But what does this have to do with pests?

All these factors can stress a plant, thereby making it more susceptible to insect damage. Proper plant nutrition is essential for preventing pest problems. (Sometimes this may mean not feeding a plant at all!)

Another way to prevent problems is to attract some of the “good guys” to your garden. Beneficial insects like ladybugs, lacewings, hoverflies and predatory wasps (among others) will work for you to control pests naturally before pest populations get out of hand. You can attract the good guys by filling your garden with a variety of plants, especially those that are specifically attractive to beneficials – like dill, calendula and mints.

In other words: IPM should be part of everyone’s gardening practices. It’ll save you time and keep you from having problems down the road. It keeps you from applying extra products, saving them for when there really is a problem. Finally, it’s a much more sustainable way to manage your yard – not to mention better for you, your plants and the environment.