Harvesting those delicious zucchini squash is one of the highlights of the summer gardening season. However, zucchini growing problems can get incredibly frustrating. Read on to learn safe, natural remedies for some of the most prevalent zucchini pests that attack your precious plants.

If you feel disheartened by a seemingly endless list of garden pests, don’t worry. There are plenty of simple solutions for most zucchini plant problems. With some proactive planning in the spring and prompt action when you spot signs of insect damage, your zucchini harvest will be safe.

Healthy plants are significantly more resilient against pest and disease problems. Therefore, providing them with appropriate light, water, and nutrients is the best defense. Keep your garden free from weeds, and be thorough in your fall cleanup to discourage insects from overwintering in the beds.

This post covers the best ways to get rid of zucchini bugs before they can damage your crops. Let’s dig in!

Best Treatments for Familiar Zucchini Pests

Zucchini, or Cucurbita pepo, is a type of summer squash in the Cucurbitaceae plant family. It’s related to cucumbers, gourds, melons, and winter squash like butternut or acorn. More examples of summer squash include pattypan, crookneck, and straightneck yellow squash.

Squash plants are easy to grow and typically recover from insect damage if the problem gets addressed in time. Common signs of plant distress from pest activity are wilting or curled leaves, discolored leaf or stem spots, and low fruit production.

When using pesticides around your garden, remember that they also affect beneficial insects like pollinators and predators. Zucchini plants depend on insects for pollination. In addition, predatory insects help to control pest populations. Spray insecticides as a last resort, and implement cultural controls like floating row covers, companion planting, and trap cropping to ward off pests.

Most Commonplace Zucchini Pests

As soon as you notice signs of insect damage, it’s critical to act fast. If only a few pests are present, hand-picking them off your plants is sufficient. Or, spray them off with a strong blast from your garden hose.

If you decide it’s necessary to spray insecticides, apply an organic, non-toxic product and target only the worst infested areas to avoid killing the helpful bugs. Use it during the early morning and late evening when pollinators are least active. Spraying when temperatures are cool also lowers the risk of leaf burn.

Insecticidal soap works against many pests and doesn’t kill beneficial insects as long as they don’t get directly sprayed. Additionally, it doesn’t leave behind any harmful residues and is simple to make with ingredients you already have at home.

DIY Insecticidal Soap

• 1 gallon of water
• 2 ½ tablespoons each of vegetable oil and liquid dish soap

Mix the ingredients in a clean spray bottle and shake to blend. If desired, add 10-15 drops of insecticidal essential oil like basil, lavender, lemon, orange, peppermint, or tea tree.

Spray all affected plant surfaces. Insects often hide on the leaves’ undersides. The soap and oil smother insects on contact during all phases of their life cycle, including eggs.

Aphids (Aphidoidea)

Aphids are one of the most frequent garden pests. They feed on plants by sucking sap from leaves, making them curl and pucker. They measure about an eighth-inch long and can be black, brown, green, pink, red, or yellow.

If you spot fluffy white bugs on your zucchini plants, they might be woolly aphids. At first glance, woolly aphids often look like powdery mildew on zucchini leaves.

Knock aphids off of your plants with a forceful spray of water. Treat a severe infestation with neem oil or insecticidal soap. Aromatic herbs and flowers like calendula, chives, cilantro, cosmos, dill, sweet alyssum, and yarrow attract ladybugs, lacewings, hoverflies, and other natural aphid predators. Basil, catnip, garlic, marigolds, and mint reportedly repel aphids.

Nasturtiums and sunflowers are effective aphid trap crops. Plant them around three to eight feet away from your zukes as a pest diversion.

An overabundance of nitrogen in plants intensifies aphids’ reproduction. Avoid over-fertilizing your zucchini plants, and always follow the directions printed on the product label.

Cucumber Beetles

There are two primary species of cucumber beetles in North America: striped (Acalymma vittatum) and spotted (Diabrotica undecimpunctata howardi). They both inflict the same kind of damage on zucchini plants, and their pest control methods are also the same.

Adult cucumber beetles are bright orange or yellow with black markings. Their eggs are orange-yellow eggs, and the larvae appear white with a dark brown head.

Cucumber beetles feed on cucurbit plants’ leaves and stems. Furthermore, they frequently spread plant diseases like bacterial wilt as they travel between plants. Companion plants that repel cucumber beetles include catnip, marigolds, nasturtium, radishes, sage, and tansy.

These insects overwinter in plant debris, brush piles, and other sheltered areas. The larvae feed underground on roots before they emerge in late spring or early summer.

To eradicate a severe cucumber beetle infestation, spray weekly with neem oil. It works as a systemic insecticide, meaning it gets absorbed into the plant tissue and consumed by insects when they feed. The active compounds cause insects to stop feeding, prevent larvae from maturing, and interrupt their mating cycles.

Spray neem oil in the evening when cucumber beetles are most active. Neem oil also kills insects on contact by smothering them. Plus, its strong scent helps to repel cucumber beetles for a week or two.

Squash Bugs (Anasa tristis)

Squash bugs are dark brown or dark gray and have a wide, flat body about a half-inch long. Zucchini leaves turn yellow or brown and wilt due to their feeding.

Squash bugs overwinter in dead leaves, wood, and other garden debris. They emerge in early June to mate and lay eggs through mid-summer. Their eggs are copper-colored and appear on the leaves’ undersides where veins come together and form a “V.” If you notice egg clusters on your plants, wipe them away or crush them before the eggs hatch. Fortunately, squash bugs only produce a single generation per year.

Adult squash bugs are challenging to eliminate with pesticides, as they can quickly escape while you’re spraying. If you tend to have severe squash bug problems in your area, treat your plants with an organic insecticide like spinosad or neem oil in early to mid-June to kill the nymphs.

Plant bee balm, catnip, marigolds, nasturtiums, radishes, and tansy near your zucchini plants to repel squash bugs. These insects frequently find shelter in debris around plants’ bases, so keep them clear.

Trap squash bugs by placing a piece of cardboard next to the plants overnight. Early in the morning, gather and kill any squash bugs you find underneath. To learn more about squash bug control, check out this article from the UC Master Gardeners of Inyo & Mono Counties.

Squash Vine Borers (Melittia cucurbitae)

Adult squash vine borer moths emerge in late spring or early summer after overwintering underground. They lay eggs near the base of cucurbit plants, which hatch about a week later. The larvae bore into cucurbit stems to feed. They’re active for several weeks before burrowing underground to pupate until the following spring.

The adult moths are black and orange with metallic green wings. Their worm-like larvae appear off-white with dark brown heads. The copper-colored eggs get laid around the plant’s base and occasionally on stems and leaves.

If just one leaf or the end of a vine becomes limp, look for a potential borer’s entry point. If there’s a small, dark hole, immediately cut away that part of the plant before the rest becomes infested, too. Check the remaining leaves and stems for eggs, as well.

Squash vine borers can be devastating to your zucchini crop. In just a day or two, the plants go from healthy and thriving to collapsing and wilting as the moth larvae bore into the stems. This article from the University of Florida has more information about squash vine borers.

Bacillus thuringiensis (Bt), neem oil, and spinosad are effective organic insecticides against squash vine borers. Treat your zucchini plants in the morning or evening while pollinators are less active. Or, apply beneficial nematodes to your garden soil to kill the larvae.

Companion plants that repel squash vine borers include basil, mint, onion, parsley, and radishes. Another strategy is trapping adult vine borers in a bright yellow bowl full of soapy water. Since squash blossoms are yellow, this color attracts the bugs.

Stink Bugs (Halyomorpha halys)

Stink bugs, also called shield bugs, sometimes get confused with squash bugs because of their similar appearance. Their bodies are rounder, wider, and darker than squash bugs. After the insects feed on their sap, zucchini leaves wilt and turn yellow or brown.

Catnip, chrysanthemums, garlic, lavender, marigolds, radishes, and thyme repel stink bugs. Unfortunately, stink bugs are impervious to most insecticides. Keep the weeds under control, and hand-pick insects off your plants when you spot them.

Stink bugs are often attracted to shiny objects. Make a DIY stink bug trap with an aluminum roasting pan full of soapy water. Place it where there’s the most insect activity.

Cultural Controls for Zucchini Growing Problems

Resolving zucchini plant problems shouldn’t mean spraying your plants with toxic chemicals. Aside from killing beneficial insects, these chemicals aren’t safe to use on plants grown for food. In particular, avoid products that contain imidacloprid or carbaryl.

Diatomaceous earth is another effective natural insecticide. However, it’s not ideal to use on zucchini plants while flowering because it kills pollinators when they touch the dust.

Many insect pests overwinter in the soil or nearby plant debris. Shifting where you plant different types of veggies each year or two is helpful, a practice called crop rotation. Cedar mulch also repels numerous pests.

Vine borers, squash bugs, and cucumber beetles reportedly prefer Blue Hubbard squash to zucchini. As such, it’s a practical trap crop to keep the pests away from zucchini plants. The trap plant should be approximately five feet away from the zucchini when the plants are full-grown. This system works best when the Blue Hubbard plant is farther along than the zucchini, so plant it two weeks earlier.

Protect your plants using a cold frame or floating row covers in the springtime to deter insects from laying eggs on them. Uncover the plants for at least an hour each day in the early afternoon once they begin flowering to facilitate pollination. Otherwise, you’ll need to hand-pollinate the blossoms.

Zucchini growing problems may seem exasperating at first, but rest assured that there are numerous straightforward options to get rid of zucchini pests naturally. Employ preventative measures like companion planting and crop rotation to help limit severe infestations. Use pesticides as a last resort, and be mindful that they negatively affect beneficial insects, too.

Do you have any questions or suggestions about eliminating zucchini pests? Please share them in the comments! If you found these pest control tips useful, please share this post about dealing with common zucchini pests with your fellow gardeners.