15 Garden Pests To Watch Out For This Season

Vine borers are a little tricky to identify because they live and feed inside the stem, but once you know the signs to look for, you can easily identify a vine borer infestation. The first sign of distress you may notice is that the leaves of your squash or cucumber vines are wilting. If you see wilting leaves, look closer to discover more vine borer signs. Prolonged vine border activity will ultimately kill the entire plant.

Inspect the stem of your plant and look for holes. The holes will be visible to the naked eye and can be a couple of millimeters across. If you look closely at the hole, it may simply look like a hole in the hollow center of the vine stem. Occasionally, however, you can see the caterpillar inside the hole, busily munching on the inner parts of the plant stem.

At the entrance to each hole, you may also see moist piles of mushy frass (insect excrement). As the vine borer caterpillar feeds, it excretes frass just outside its hole, giving you a fairly obvious external clue about what lurks inside. If you have multiple borers in a single vine, each borer will have its own personal hole, so each hole you see along the vine represents a hungry vine borer caterpillar.

• Carefully slit the stem at the entry hole and remove the caterpillar with thin, pointed tweezers.
• Inject Bt (Bacillus thuringiensis) into infested plant stems at 1/2″ increments along the stem.
• If your vines are growing along the ground, cover sections of the vine with a pile of soil to encourage rooting. If the lower vine sections die because of vine borers, you will have a rooted, healthy section to continue growing.
• Use a floating row cover early in the season to prevent the flying adult moths from laying eggs on your vines. Remove the row covers when plants start flowering because they will need access to pollinators.

You may not notice the first few aphids, but the symptoms become much more obvious once you have a bunch. You may see the insects congregating on the leaf surface, undersides of the leaves, and on stems. As aphids feed, they secrete a sticky clear liquid called ‘honeydew,’ which may appear as wet or waxy-looking spots on the leaves of your plants.

As the adults and nymphs feed on the plants, sucking their juices, they cause the leaves to curl and turn yellow. Sometimes leaves appear stunted or deformed, and it’s important to note that this only affects the leaves on which the aphids are actively feeding, while unaffected leaves still appear normal and healthy.

Heavy and prolonged infestations will eventually harm the entire plant. The plant may wilt, and fruits and flowers can become stunted and deformed. The honeydew secretions can lead to fungal infections, where you’ll notice black or gray mold on the leaves and stems of your plants.

• Ladybugs and other beneficial insects love to eat aphids. Attract beneficial insects to your garden by planting pollinator-friendly plants and avoiding pesticides.
• Spray infected plants with a jet of water. This will dislodge and disturb feeding insects, making it harder for them to cause severe damage.
• Spray concentrations of aphids with insecticidal soap or neem oil.

Many birds are beneficial for the home landscape, and these birds are welcome visitors. But if you have some nuisance birds eating your favorite crops, you may want them gone.

• Woodpeckers: Check for neat round holes drilled in trees as a clear sign of woodpecker damage. Woodpeckers also sometimes drill into fences and other wooden structures and drill on houses.
• Ground-foragers: Some ground-foraging birds will dig up and eat freshly sown seeds.
• Fruit-eaters: Frugivorous birds will eat berries and grapes and may also peck into other soft fruits like tomatoes.
• Large birds: Larger birds, like crows, starlings, and blackbirds, will damage and eat crops such as corn and melons.

• Use floating row covers to protect freshly seeded areas.
• Try a critter cage over young or small plants.
• Plant more than you need to share some with the resident wildlife.
• Keep bird feeders away from your garden plants.
• Try bird-scare tactics such as rubber snakes, reflective spinners, and fake owls.

Caterpillars eat plant foliage, and they consume it very quickly. A single caterpillar can defoliate an entire small plant, leaving nothing but the stem. Check your plants regularly, and if you see leaf edges with large chewed holes, start looking for caterpillar culprits. If you don’t see the caterpillars, you may notice some of the frass (excrement) they leave behind as small greenish or brownish nuggets that may remain on the leaves.

Identify if the caterpillars are pests or if you want to encourage them. Most people consider tomato hornworms pests but are willing to share parsley leaves with swallowtail butterfly caterpillars.

• Hand-pick individual caterpillars. Tomato hornworms may look scary, but they are totally harmless to humans.
• For brassica-eating caterpillars, spray infected plants with Bt (Bacillus thuringiensis). You can also use Bt spray on plants that flower, but avoid spraying it onto flowers to prevent even tiny risks to pollinators.
• Cover susceptible young plants with floating row covers to prevent adults from laying eggs. Note that on flowering/fruiting plants, this may keep your pollinators out too!
• Encourage beneficial insects.
• Grow companion plants known to repel pests.

You will see adult beetles on your plants if you have cucumber beetles. They are active during the day and freely feed on plant leaves. You may notice a few or many small holes chewed in the fruits and leaves. Cucumber beetles prefer cucumbers but will also feed on other melons and cucurbits. You may also see them on other plants, but their favorites are squashes and cucumbers.

Beetles can transmit bacterial wilt, causing the entire plant to wilt and die. If you notice your plants wilting and spot some cucumber beetles, the plants may already be infected by the bacteria. If the plant seems to be dying, it may be best to remove and dispose of the entire plant. To prevent the further spread of pests and infections, put it in the trash rather than your compost; bacteria can colonize your compost pile.

• Use floating row covers to protect young plants.
• Remove leafy debris where pests may overwinter.
• Grow disease-resistant varieties of squash and melons.
• Start cucumbers later to avoid early-season infestations.
• If necessary, a spinosad spray (an organic pesticide made from two forms of soil bacteria) can be used to eliminate cucumber beetles.

Signs of deer will be partially eaten plants, or the entire plant may disappear. Along with missing plants, you will also notice deer hoof prints, particularly in soft soil, and large oval pellets of deer scat. You will also probably see the deer as they wander around your yard. If you know deer are around, and you see your plants are eaten from the top down, you can safely assume deer are causing this damage.

Install a fence at least 6 to 8 feet tall around your vegetable garden.

Try deer repellant sprays with a taste that deer don’t like. These will need to be reapplied after each rain.

Applications of predator urine at the boundaries of your garden may keep them at bay but will need to be reapplied regularly.

Do not offer special foods or salt licks to feed the deer; these only attract them to your yard.

Grow deer-resistant plants.

If you have flea beetles, the first thing you are likely to notice is small shothole patterns in the leaves of your plants. Unlike caterpillars that usually eat from the outside edge, flea beetles create many tiny holes throughout the entire leaf, not just along the leaf margins. Certain plants, such as eggplant and turnips, may be almost completely defoliated by an infestation of these tiny beetles.

The beetles are small, but you can see them moving around on the leaves. When you disrupt them, they jump up like fleas. Light infestations may cause some small holes, but larger infestations can cause the loss of entire leaves.

Damaged leaves may develop larger dead patches that turn brown, or leaves may become stunted or deformed. Flea beetles can also transmit the bacteria that causes bacterial wilt, in which case the entire plant can become diseased and die.

• Wait for seedlings to grow large before transplanting, giving them extra resistance against these pests.
• Use row covers to protect young plants from pests, but uncover your crops when they start to flower because you will need to allow pollinators to visit.
• Flea beetles are most active in early spring, so delay plantings of susceptible crops to avoid the worst season.
• Selectively spray infected plants with insecticidal soaps.
• Beneficial nematodes can be added to the soil to help control the tiny grublike larvae.

Damage caused by Japanese beetles is obvious, as are the beetles themselves, so you should have no trouble confirming if these pests are in your garden. Adult Japanese beetles are not shy and wander freely during the daytime, so you will likely see them if they are around. They primarily walk on the plant’s surface but fly from plant to plant. When disturbed, they will either fly away or release and drop off.

Japanese beetles tend to congregate in groups. A group of feeding beetles can quickly cause damage to plant leaves. You will see their chewed holes throughout the leaf surface. Eventually, they will skeletonize the entire leaf, so all you have left is its remaining browned veins. When the beetles finish one leaf, they move on to the next. Japanese beetles rarely kill larger plants but can cause extensive damage.

• Hand-pick adult beetles and drop them into a bucket of soapy water. This is very effective for small infestations.
• Spray adults with a hard stream of water to interrupt their feeding.
• Avoid plants most susceptible to Japanese beetle infestations (such as roses, grapes, apples, cherries).
• Select trees that are not favored by Japanese beetles (such as dogwood, maple, holly).
• Use trap crops to attract large numbers of beetles, then spray or dispose of these plants.
• Applying beneficial nematodes to the soil can help eliminate any grubs in the off-season.
• Some people use milky spore powder, but it can take years to become established in the soil and prevent grubs from overwintering.

Mealybugs can be easily identified if you check your plants regularly. Look for small gray or white insects, sometimes individually but often congregated in patches. You will also see a clear, sticky fluid called ‘honeydew’ that they excrete as they feed. This will appear as wet or waxy spots on the leaves. Ants feed on the honeydew, so you will often see small ants crawling around on infected plants.

A heavily infested plant will show obvious signs of distress. You may first notice a yellowing of the leaves, followed by leaf drop. New leaves may also appear curled or deformed. As the infestation progresses, plants can eventually die, and mealybugs will easily spread from one plant to neighboring plants.

• Before adding new plants to your collection, inspect them closely to be sure you aren’t introducing any new pests.
• Encourage and support beneficial insects that feed on mealybugs.
• For small infestations, remove insects by hand, using a cotton swab dipped in rubbing alcohol.
• Spray jets of water on infected leaves to disturb feeding adults. This won’t kill them but can help keep their numbers manageable.
• Neem oil can be used as a preventative on leaf surfaces. Only apply a light misting, and do not use neem or any other horticultural oil when the temperature is over 85 degrees on any full-sun plants.
• Use insecticidal soap to target dense clusters of feeding mealybugs.

The primary sign of moles you will notice is their long tunnels of disturbed earth. Yesterday, your lawn was smooth and flat, and today there is a network of tunnels pushing up the grass and soil. Those tunnels are likely the work of moles. Plants disturbed by the tunnels may dry out faster and become yellow and dry.

• Grow castor beans around your garden area as a way to deter moles. There is some evidence that moles avoid areas where castor beans are growing.
• Moles like burrowing in the dry earth. If you discover a fresh burrow, you can try flushing the mole out by running water into the burrow. If you can catch the mole, put it in a bucket and relocate it a few miles away if your region does not have laws preventing rehoming wildlife.
• Consider raised bed gardening. If installed before filling a raised bed, some hardware cloth or a metal mole or gopher mesh will prevent moles from accessing your garden bed from below.
• Bury fencing 2 feet below the soil’s surface around your entire garden. This is a lot of work but can effectively block moles from a specific area.
• There are a variety of no-kill mole traps on the market which may be worth a try.

In many areas of the country, you will see rabbits in urban, suburban, and rural areas. You may also notice their small round droppings in your lawn and garden. If you see rabbits or signs of rabbits, you will know they are likely snacking on plants in and around your yard.

Rabbits eat the leaves of a great variety of plants. Sometimes they will take a small taste and then move on. Other times they will consume entire leaves and plants, often eating from the top down. They may chop down your tall-stalked flowers by biting through the stem or eat the tops of your young and low-growing bedding plants. Rabbit damage can be quite extensive.

• Use wire critter cages to protect smaller plants.
• Put a 2-foot tall wire fence around your garden to protect the plants within. Consider using a 3-foot wire fence and burying a foot of it to prevent the rabbits from digging under the fence to gain access.
• Use tall raised beds to grow plants above the rabbit’s reach.
• Discourage rabbits in your landscape by removing brush piles and unkempt weed patches.
• Consider using predator urine to deter rabbits. This requires regular reapplication of the urine to be effective, but may not be a long-term solution.
• Spray valuable plants with a rabbit deterrent, such as capsaicin, that has a taste rabbits don’t like.
• Trapping isn’t particularly effective because, for every rabbit you remove, another one moves in to take its place.
• Grow plants that rabbits don’t like to eat.

If you check your garden after the sun goes down, you are likely to encounter slugs and snails. If you see these animals creeping along, they are likely heading to a meal on some plant matter nearby. Even if you don’t see the adults, you may notice their slime trails, a sign that slugs and snails are present.

Slugs and snails chew holes in soft plant parts, especially leaves and fruits. Occasionally they will even eat through a stem causing the entire leaf to fall off or dangle from a thread. Slugs will chew large and irregularly shaped holes in leaves, which looks different than damage from tiny chewing insects. Slugs particularly like hosta leaves and will chew numerous holes in these plants each night.

• Hand-pick any slugs and snails you see feeding at night to keep the population low.
• Use traps; collect and dispose of dead slugs promptly.
• Use a copper strip barrier to deter slugs. Note that this is only effective on raised beds.
• Use an organic slug or snail bait to create a ring around your garden. They will consume the bait and not your plants.

If you have squash bugs, you will probably see the insects themselves, as well as their eggs. They are not shy and you will see them feeding during the daytime. If you see large insects walking around on the leaves of your melons and squash, there’s an excellent chance they are squash bugs.

Check both the leaves’ tops and the leaves’ undersides for signs of squash bugs, including adults, smaller grayish juveniles, and clusters of small oval-shaped eggs attached to the leaf surface.

Leaves of infected plants will start to look weak and limp, then quickly turn yellow and brown, and then die. Smaller and younger plants are more susceptible to squash bug damage and can be killed quickly, whereas older plants may have a bit more resistance later in the season.

• Hand-pick squash bugs and drop them in a bucket of soapy water.
• Use a butter knife to scrape egg clusters off the plant and drop them into soapy water.
• Apply a neem oil or horticultural oil to smother egg clusters so they cannot hatch and to deter feeding.
• Remove leafy debris at the end of each growing season where pests might hide and overwinter.
• Check your plants frequently and remove any insects or eggs you see.

If you live in an area with squirrels, you have probably seen them running around, climbing trees, crossing streets, and digging holes in the ground. Squirrels dig, chew, and munch, and their signs are pretty obvious.

Squirrels love digging in soft, loose soil, so if you have planted seeds or seedlings only to come out later and see they are dug up, squirrels are a likely culprit. Squirrels also love eating fruits like strawberries, tomatoes, and apples.

They may carry off the entire fruits, eat large chunks and leave the rest on the ground, or eat chunks out of your fruits while they are still attached to the plant. Squirrels also chew on stems, branches, twigs, and tender leaves.

• Protect smaller plants by covering them with a critter-proof cage.
• Try spraying the squirrels’ favorite plants with capsaicin to repel them. Sprays will need to be reapplied after each rain.
• Trapping is not effective with squirrels because another squirrel will immediately take the place of any that are removed.
• Don’t attract squirrels to your yard by offering bird feeders or squirrel corn; you will only have more hungry squirrels looking for more food.
• If you feed birds, place bird feeders away from your garden.
• Pet dogs are a surprisingly good deterrent for squirrels and will patrol for you!

You may already have thousands of mites when you notice the spider mite infestation on your plant. The first visible sign of spider mites is usually a discoloration of the leaves. A typical healthy green leaf will take on a yellowish, mottled appearance as the mites suck out the juices. The yellowing may be patchy or throughout the entire leaf.

As the damage grows and spreads, you may see leaves curling around the edges, and young leaves will emerge deformed and crumpled. You may also see damage to flowers and stems.

Vast numbers of spider mites create a network of thin threads that you can see on the leaf surface, along the stems, or particularly at the joints between leaves and stems. You can also see the mites in the webbing and along the surfaces and undersides of infected leaves. Severely infected plants will eventually die.

• Check plants regularly for pests and take action quickly to prevent worsening. Gently shaking foliage with symptoms of spider mites over a white piece of paper can dislodge some onto the paper, helping you identify that they are there.
• Spider mites target weakened and stressed plants, so keep your plants healthy by watering them regularly, mulching around them, and choosing the best plants for your site.
• Spray infested plants with a jet of water to dislodge mites and disrupt their feeding cycle.
• Encourage natural mite predators and beneficial insects by planting various pollinator-friendly plants and avoiding generalized pesticide applications.

• Keep your plants healthy by pulling weeds, offering enough water, and giving them plenty of space.
• Don’t compost insect-infested materials to keep pests from spreading.
• Remove leafy debris each fall so pests can’t overwinter in your garden.
• Check your plants frequently for any signs of pests and diseases.
• Treat pests and diseases promptly.
• Rotate crops each year.
• Grow companion plants that are reputed to repel or deter pests.

Although there may seem to be a disproportionate number of bugs trying to destroy your crops, not all insects are harmful. In fact, the majority of insects that visit your garden are not pest species. Many insects are welcome in the garden because they prey upon nuisance pests or they are pollinators. Ladybugs, praying mantids, lacewings, parasitic wasps, butterflies, bees, and spiders are all beneficial. These creatures help with pollination, and many feed primarily on insect pests. Ways to attract beneficial insects include:

• Don’t use chemical pesticides unless absolutely necessary.
• Grow pollinator-friendly plants from diverse families.
• Grow a variety of different plants, including trees and shrubs.

Most insects that you will see using your garden are not pests. One danger of spraying your plants with pesticides is that many pesticides will kill all insects, not just the ones you want to target!

Organic pesticides are generally faster to break down so have a limited efficacy, but also can be indiscriminate. For instance, Bacillus thuringiensis (BT) is great against caterpillars — but it kills all caterpillars, whether or not they are Monarch butterfly caterpillars or tomato hornworms. Limiting their use to only when they’re necessary is ideal, and avoid plants you intentionally are growing for pollinators.

When you absolutely need to reach for a pesticide, spray in the evenings when pollinators are not active. Organic options are often harmless to pollinators once they’ve dried on the plant, but this is not universally true. Target only the pest-infested plants rather than spraying everything, and if possible, avoid spraying actively-blooming flowers on the plant. This will best focus on the pests you’re trying to eliminate. Use chemical pesticides as a last resort, and only sparingly; these are more potent and can cause residual damage to your beneficial pest populations.