Integrated Pest Management: Preventing Bugs From Destroying Plants

Bugs on plants are more than a nuisance. They damage plants by sucking out sap, destroying leaves and transmitting diseases. I’m all for a balanced ecosystem, and I realize bugs gotta eat too, but there’s a point at which I have to choose between the bug and being able to eat the cucumbers I have spent time and precious water nurturing from seed. I might not be smarter, but I’m bigger and I have tools and creativity.

For many years in the past, home gardeners like us relied on chemicals to kill a bug at the first sign of trouble, and I’m so glad that the concept of integrated pest management, or IPM, has replaced that approach for so many people who care about the food they eat, the environment and preserving beneficial insects.

cucumber beetle
Cucumber beetles like any yellow flower, including the ones on this honeydew melon. This is the last known photo of this particular beetle…

Let’s break down a rather fancy term into the basics: start with the least harmful control. It’s really the same as prevention in medicine. Ward off a disease as your first choice instead of having to go through treatment. Here are the basic steps:

1. Start with healthy plants and good cultural management. This is the most important step to try to prevent insects in any yard or garden. First and foremost, plant native plants. I’ll never stop repeating this mantra. When you include plants adapted to your environment, they’re less likely to get stressed. There’s lots of research on the plant stress hypothesis because I guess some people disagree with it. But prevailing thought seems to be that plants stressed by drought or other conditions are more vulnerable to bug infestations and damage. It makes sense, and it’s still better to keep plants healthy anyway for flower or fruit production. Be sure to rotate crops, plant a variety of plants, and place plants in the right conditions based on shade or sun requirements, for example.

healthy tomato in container
This grape tomato plant is healthy and happy. It’s in a container with rich soil. I think it’s a little easier to control pests with containers.

2. Keep bugs away by weeding as much as possible and cleaning up debris to prevent hiding places. And cover seedlings with tunnels and row covers (with no holes) to keep bugs off while the plants are young and more vulnerable. Make sure plants are not too close together so they have airflow and can dry out as needed. Use mulch to cool roots and hold in water and compost to enrich soil. If one plant gets a disease, remove it from your garden and throw it out. Don’t lay it near the garden or compost it.

Covered seedlings
These lettuce seedlings have green beans for shade and cloth to keep bugs out until they get a little larger.

3. Hand pick bugs that appear if you can. This is not always easy, but if I can touch bugs, anyone can. Home gardeners who visit their garden regularly to water, deadhead flowers and check or harvest vegetables should inspect for bugs, especially in the morning. A major advantage of handpicking is that you can pick just the bad insects, causing no harm to beneficial bugs on your plants, who are there helping in your cause. See my Resources page for a few links to articles or photos that help identify beneficial insects. And here’s what I do when I pick off the little bug – throw it in a container of dish soap and water. I like to reuse a plastic container with a flip lid each year for easy, one-handed entry. Last year, it was an empty sanitary wipe jar. This year, I had used nearly all of my taco spice mix from Costco. I put the rest in a plastic zipped bag and had an instant bug bath. A blister bug infestation at our community garden one year had Tim and I doing a “swipe and boot stomp” method because those monsters bite and because of pure numbers. Our neighbor finally had to vacuum the potato plants.

dish soap and water for handpicking bugs in the garden
The little beetle featured in the photo above got a spicy ending courtesy of my handmade holding cell. All that’s inside is environmentally friendly dish soap (because that’s what I had), some water, and taco seasoning residue. The top snaps open.

4. When all else fails and you must use a pesticide, there are several organic choices. It’s also important to know that although an insecticide is organic, it still can be harmful, especially to bees and other beneficial insects. The three we keep on hand are insecticidal soap, Neem oil and Diatomaceous earth. Still, it’s recommended only to use these products once you have identified the pest or really have to do so. For example, I can spray a plant with water first to stop aphids before resorting to soap. I encourage reading labels carefully for time from use to harvest for any edibles, for specific pests they destroy and for any cautions about other insects, pets or warnings.

diatomaceous earth on ant hill in garden
This poor pepper has been attacked already by a gopher (and poor watering because it all floods down the hole the critter left behind). Now the stressed plant has an ant hill below. I am trying diatomaceous earth to stop them from doing more damage.
natural pesticide choices
Diatomaceous earth stops crawlers, and soap and oil can stop flying insects.

Further, you can’t be perfect at IPM cultural practices, as hard as you try. For example, I’m pretty sure tomatoes are not native to my region. But I want a vegetable garden. I have to work harder to keep tomatoes healthy than I do the ornamentals (and weeds!) native to New Mexico. I also can’t control the weather. I’m certain many of our bug (and snail!) trouble occurred during frequent night rains and cool, cloudy days. Our plants aren’t adapted to that. Finally, we spend most of our time on weeds – mowing, pulling and preventing. But we can’t control all of the weeds, nor can we control what our neighbors do with weeds or chemicals.