How to Solve Garden Insect Problems

Garden pests are an unfortunate reality in any garden. You may not have problems every year, but eventually some insects or other pests will discover your tasty veggies and help themselves. But, you don’t have to take their attacks lying down! Here are some tips on how to solve garden insect problems for some of the most common offenders.

Solve Tomato Hornworm Problems

This is like the classic cartoon with a caterpillar eating your veggies. Especially your tomato plants, although they can also eat potatoes, peppers, and eggplants. The tomato hornworm is the larval form of the five spotted moth. They start out yellow or white, but usually turn green as they get larger with v-shaped white markings and have a distinctive horn shape on the end of their abdomen. They are one of the largest garden insect pests and can grow up to four inches long. Just one of these beauties can strip the leaves off of a whole tomato plant almost overnight.

The good thing about their large size and voracious appetite is that their damage is relatively easy to spot. They feed mostly at night, but a telltale sign you might see during the day is their dark green or black droppings on leaves or around the base of the plants. They are well camoflaged, but they actually glow under UV light, so you might try hunting for them after dark with a black light. Picking them off by hand and putting them in a bucket of soapy water, or feeding them to your chickens can be an effective way to solve this garden insect problem. But, you need to check your garden a couple times a week to make sure none of their friends have returned.

Solve Japanese Beetle Problems

This invasive species has been in the U.S. for over a hundred years, but has only slowly moved from the East Coast across the country. These half-inch long beetles have a metallic green head and body with copper colored wing tips. They will eat almost anything in your garden, but seem to especially like grapes, roses, apples, cherry, hazelnut, and bean plants in our garden. I also find them hanging out on asparagus plants, although they don’t seem to do much damage to them. They eat the green parts of the leaves between the veins leaving a leaf skeleton behind. Luckily mature trees or shrubs can usually withstand significant leaf damage, but vegetables can be severely damaged.

They are easy to spot once they emerge in mid-summer and are relatively slow flyers, especially in cool mornings or evenings. They spend most of their adult lives eating and mating, before the females burrow into the ground to lay eggs before fall. I like to solve this pest problem by knocking bucketloads off of my plants into soapy water. But you will need to keep doing it for the 6-8 weeks that they feed each summer. My chickens love when I dump the buckets into their coop at the end of a good beetle capturing session. There are also insecticides you can use, but most of them also kill many beneficial insects, so I try to avoid using them if possible. Luckily the beetles are usually done by mid-August in my area and most of my plants are able to survive and recover enough to still get a good harvest before our first frost.

Solve Aphid Problems

These common garden pests are small insects with soft bodies that attach themselves to your plants’ stems and suck their juices. They come in a variety of colors and sizes, but light green, yellow, brown, black, and grey are pretty common. Most plants can survive an aphid infestation, but it can cause localized damage or curling leaves. Plants that are already weakened by disease or other pest damage could be more severely affected. Aphids can also carry some plant diseases like the cucumber mosaic virus and spread it from plant to plant in your garden.

The classic way to solve this pest problem is with beneficial insects like lady bugs. You can introduce some into your garden, or let a large number of aphids attract their own predators. Another good method is to use a high powered spray of water to knock the aphids off of your plants. Even a hard rainstorm can wash them off sometimes. Keeping weeds away from your plants can also help prevent aphid infestations by keeping other food sources of the aphids away.

Solve Potato Beetle Problems

The Colorado Potato Beetle can be a major problem for your potatoes, tomatoes, and eggplants. These half-inch long beetles with orange bodies and white and black striped wing covers lay tons of eggs on your potato plants which hatch out bright red larvae who will devour potato leaves rapidly. Unfortunately, they like to attack right when your potatoes need to be putting all their energy into bulking up their underground tubers and losing a significant number of leaves can really decrease your harvest.

One of the best ways to solve this garden insect problem is to monitor your potato plants closely and destroy any beetles or eggs you find early in the year. If you don’t catch them then, the bright red larvae are easy to see and squash, but it can get messy. If you catch the larvae when they are small, they can do much less damage to your plants. Mulching around your potato plants can also help disrupt the life cycle of the beetle. Plus moving your potatoes to new areas of your garden each year can make it harder for the beetles to find them in the spring. You can also use row cover in the spring to prevent the beetles from laying eggs on the leaves.

Solve Cabbage Moth Problems

There are several different varieties of moths that love to lay eggs on cabbage, broccoli, kale, and other brassica family plants. The small green caterpillars that hatch can chew unsightly holes in your salad greens and if you have enough damage, even prevent your cabbages, cauliflower, or broccoli from forming heads. The moths are usually white or yellow and about one and a half inches wide. You will see the moths flitting around your crops during the day or at night, depending on the variety of pest common in your area.

One of the easiest ways to solve this garden insect problem is to remove any caterpillars you see on your crops. We carefully pick through any salad greens coming in the house because at certain times of the year, we’re sure to find at least one in a batch. You can also install row covers over your crops to preven the moths from laying eggs on the leaves. Luckily these crops don’t need pollination, so you can leave the row covers on all the way to harvest. There has also been some positive evidence of using decoy moths, and some gardeners swear by interplanting smelly herbs like thyme with your cabbage family plants to repel the moths.

Solve Squash Vine Borer Problems

These sneaky and distinctive looking pests lay their eggs in the stems of all different kinds of squash and pumpkins. The half-inch bugs with orange bodies and metallic colored wings look like wasps, but are actually in the moth family. The larvae hatch and chew through the centers of the squash stems blocking the transport of water and causing the leaves to suddenly wilt. Eventually the whole plant will die. If you are able to find and remove the larvae, you can sometimes mound dirt over the plant and get the vine to re-root and continue growing. However, more than one larva can attack a single vine.

Row covers can keep the moths from laying eggs on your plants during the first few weeks after they emerge, but this will only work if you rotate your squash beds. The larvae overwinter underground, so if there were squash in the bed the year before, the adults could emerge under your rowcover. You need to remove the rowcovers once your plants start flowering or they won’t get pollinated. Another way to solve this garden insect problem is to plant varieties like butternut, melons, or cucumbers that squash vine borers don’t enjoy. Or to put your squash seedlings out later in July after the adults have laid their eggs. Your local extension service may have information about when these pests typically emerge each year in your area.

OK, now you have a plan of attack for six of the most common pests. Plus a quick guide on how to solve garden insect problems. I hope you never have to use any of these solutions and your plants thrive pest-free all summer long. But if not, get out there with your row covers, soapy water buckets, or other pest control methods and fight to save your plants!

Something else eating your plants? There are other garden pests besides insects. Check out How to Protect Your Garden from Pests and Critters for more.