7 Garden Pests to Watch Out for This Summer—And How to Keep Them Away Before They Harm Your Plants

It’s heartbreaking when the nearly ready-to-harvest lush lettuce and tender tomatoes you've nurtured for months are ravaged by rodents or destroyed by bugs.

Some garden pests are common and relatively easy to manage, while others can quickly cause significant damage. Identifying some of the worst garden pests can help you take swift action to protect your plants.

Slugs and Snails

Slugs and snails may move slowly, but these slippery creatures can be a nightmare for cool, moist, shady summer gardens.

Overnight, a group of hungry slugs can cause major damage to seedlings and the leaves, flowers, and fruit of many plants. It’s important to stay vigilant, recognize the signs of a slug infestation, and quickly take steps to control them.

You can try avoiding soggy soils, using trap boards, growing veggies under cold frames, and creating a slug barrier with copper foil or bands. Slug baits can be effective but often contain metaldehyde, which is toxic to pets and wildlife, unsuitable for vegetable gardens, and harmful to the environment.

Want more gardening tips? Sign up for our free gardening newsletter for our top growing tips, troubleshooting hacks, and more!

Slug-Resistant Species

Having lived in rainy Scotland, I recommend choosing slug-resistant species in prime mollusk habitats. Some examples include bleeding hearts, endive, foxgloves, ferns, and sedum.

Caterpillars

While caterpillars munching on your plants rarely kill them, rapid defoliation leads to an unsightly appearance and stunted growth. In vegetable gardens, caterpillar infestations can result in unhealthy harvests and poor yields.

Despite being slower than some other caterpillars, the cabbage worm is one of the worst pests. These cabbage lovers can decimate your entire crop if left untreated.

Encourage beneficial predatory insects, such as lady beetles and parasitic wasps, by planting species that attract these pollinators. Also, consider using a naturally derived and effective insecticide, like Bt (Bacillus thuringiensis), rather than harsher chemical treatments for caterpillars.

Don't Miss

Aphids

If you’ve never faced an aphid infestation in your yard, consider yourself lucky. These top plant pests are widespread across the country and indiscriminately feed on a variety of species.

An outbreak of sap-sucking aphids can lead to weak and stunted growth, discolored and curling leaves, and the spread of plant diseases.

There are several ways to manage aphids, including regular monitoring for early intervention, avoiding high nitrogen fertilizers, washing them off with water, and applying insecticidal soaps.

Spider Mites

Controlling sap-sucking spider mites can be tough once a heavy infestation takes hold. To avoid these common pests from causing unsightly leaf stippling, discoloration, and drop, be proactive with integrated management techniques.

Regularly inspect for these tiny pests—a hand lens can be very helpful. Consider introducing spider mite predators, such as lady beetles or big-eyed bugs, and ensure adequate irrigation—spider mites thrive in dry conditions.

While insecticidal soaps can help control spider mites, use chemical pesticides with care. Broad-spectrum treatments can kill their natural predators, potentially causing spider mite outbreaks.

Groundhog

Groundhogs might look cute, but they are among the worst garden pests. Just a couple of these robust rodents can destroy your vegetable patch in a day, as they can consume over one pound of plant matter daily.

Their extensive burrowing can also wreak havoc on your lawn and flowerbeds and can even cause foundation damage in extreme cases.

Getting rid of groundhogs can be tricky, and prevention is often more effective. Consider tall fencing buried deeply in the ground and removing tall vegetation where groundhogs can hide.

You can also try commercial repellents, motion-activated water sprinklers, and protecting your crops with cloches and row covers.

Raccoons

These veggie vandals are opportunistic scavengers that can ruin your garden and tear up your lawn while foraging for soil-dwelling bugs.

Corn is a big favorite, and if you grow it, you'll need to adopt savvy strategies to keep raccoons away.

Consider adding an electric border to the top of your fencing, laying bird netting over your plants, applying an insecticide to grub-populated lawns, regularly spraying predator urine (such as coyote urine) around your yard, and promptly harvesting protected fruits and vegetables.

Deer

If you live in a rural area, one drawback may be the damage deer can do to the ornamental plants, trees, and shrubs in your yard.

A single deer can consume up to 10 pounds of greenery a day, stripping entire shrubs or a whole bed of flowering perennials. Male deer also cause damage by rubbing their antlers against trees, stripping off bark and potentially harming the tree.

To keep deer out of your yard, plant deer-resistant flowers and shrubs. Robust deer fencing is another effective, though expensive, solution.

Alternatively, you can install a fishing line around your vegetable plot or prized plants or cover them with cages or row covers for lower-cost protection.

When to Call a Professional

If you’re dealing with persistent pests you just can’t get rid of, especially if they’re causing extensive damage to your landscape or property, consider calling a wildlife or pest control professional.

They can help you legally and humanely trap wildlife or block them from entering your yard and have the knowledge and tools needed for targeted treatment of severe infestations.