How To Get Rid Of Pickleworms

If you’ve found telltale holes and frass in your squash, melons, or cucumbers, you’re likely dealing with pickleworms. Learning how to get rid of pickleworms is essential to saving your harvest, and the good news is that organic methods can be very effective.

These pests are the larvae of a night-flying moth. They burrow into flowers, stems, and fruits, causing rapid damage. Once inside the fruit, they’re protected, so timing and prevention are your best tools. This guide will walk you through proven, natural strategies to protect your garden.

Your control plan should be layered. Start with prevention, move to monitoring, and use physical and biological controls before fruit forms. Consistency is key, as moths lay eggs over a long season.

Correctly Identify the Problem

First, make sure it’s pickleworms. The adult is a moth with a wingspan of about one inch. It’s yellowish-brown with a purplish sheen and flies at dusk. The larvae start cream-colored with dark spots, then turn greenish as they mature.

Look for small holes in flowers and buds.
Check for sawdust-like excrement (frass) near holes.
Damaged fruits often ooze sap and rot quickly.

Confusing them with squash vine borers is common. Borers target the base of stems; pickleworms target the fruit and flowers.

Start with Smart Garden Hygiene

Clean gardening practices disrupt the pest’s life cycle. This is your first and cheapest line of defence.

Remove and destroy infested fruits immediately. Bury them or bag them for the trash—don’t compost.
At season’s end, remove all spent vines and plant debris where pupae might overwinter.
Till the soil in fall or early spring to expose and destroy buried pupae.

These simple steps significantly reduce the local population for next year.

Use Floating Row Covers as a Barrier

This is one of the most effective physical barriers. Row covers are lightweight fabrics that let in light and water but block insects.

Install hoops or frames over your cucurbit plants right after planting or transplanting.
Drape the fabric over, securing the edges tightly to the ground with soil, rocks, or pins.
You must remove the cover when plants start to flower to allow for pollination by bees.

This window of protection prevents the initial egg-laying on young plants.

Encourage Beneficial Insects and Birds

Nature provides its own pest control. Many insects and birds prey on pickleworms in their egg or larval stages.

Plant nectar-rich flowers like alyssum, dill, and fennel to attract parasitic wasps and predatory beetles.
Provide bird baths and shrubs for shelter to invite insect-eating birds into your garden.
Avoid broad-spectrum pesticides, even organic ones like pyrethrin, during the day when benificial insects are active.

Apply Organic Sprays and Treatments

When monitoring shows activity, targeted sprays can help. Always spray in the late evening to protect pollinators.

Bacillus thuringiensis (Bt)

This is a natural soil bacterium that is toxic to caterpillars when ingested. It’s safe for people, pets, and beneficials.

Use the kurstaki strain (Bt-k).
Spray thoroughly on leaves, stems, and especially flowers where larvae feed.
Reapply every 5-7 days, or after rain, as it breaks down in sunlight.

Spinosad

Another fermentation-derived product, spinosad is effective against young larvae. It is organic but can harm bees if sprayed directly on them.

Apply only in late evening when bees have returned to their hives. It retains its potency for about 24 hours before becoming safe for bees again.

Neem Oil

Neem acts as an antifeedant and growth disruptor. It works best on very young larvae and can deter egg-laying moths.

It needs to be applied consistently, about once a week, and it’s less effective on mature larvae that are already inside fruit.

Try Trapping and Handpicking

For smaller gardens, direct intervention is feasible and impactful.

Use yellow sticky traps to monitor for the adult moths.
Go out at night with a flashlight to handpick any larvae you see on leaves and buds. Drop them into soapy water.
Check inside male flowers in the morning, as they are a favorite early hiding spot.

This method requires diligence, but it can make a big difference if you stay on top of it.

Choose Resistant Varieties and Time Planting

Some cucurbit varieties are less suceptible or mature faster than others.

Butternut squash has a solid stem end that is harder for larvae to penetrate.
Plant as early as possible in your season to harvest before pest pressure peaks in mid-to-late summer.
Succession planting a fall crop after the peak moth season can also yield a clean harvest.

Set Up Pheromone Traps

These traps use a synthetic version of the female moth’s scent to attract and capture males. This reduces mating and egg-laying.

Place traps at the garden perimeter just as vines begin to run.
Check and replace the pheromone lure according to the package instructions.
Use them as a monitoring tool to know when moth flight begins, signaling you to intensify other controls.

They are more effective for monitoring than for complete control in large areas.

Maintain a Consistent Monitoring Schedule

Your eyes are the best tool you have. Establish a simple routine.

From early summer, check your plants every 2-3 days.
Examine the undersides of leaves, flowers, and small fruits for eggs or tiny larvae.
Keep a garden journal to note when you first see damage each year; this helps plan for next season.

Early detection means you can act before the worms get protected inside the fruit.

FAQ: Organic Pickleworm Control

What plants do pickleworms eat?

They prefer cucurbits: cucumbers, squash, pumpkins, melons, and gourds. Zucchini and yellow squash are often hit hardest.

Will diatomaceous earth kill pickleworms?

It’s not very effective. Diatomaceous earth works on insects that crawl on dry surfaces. Pickleworm moths fly to the plant, and larvae often go directly into buds or fruit, avoiding the dry powder.

Can you eat squash with pickleworm damage?

You can cut away the damaged portion, but the frass and decay quickly make the fruit unappetizing. It’s usually best to remove and destroy infested fruit to prevent further spread.

When are pickleworms most active?

In most regions, moth flights and infestations peak during the warmest, humid months of mid and late summer. They are not a problem in cool weather.

Does companion planting help repel them?

Strong-scented herbs like mint or radishes planted nearby may offer some minimal deterrent effect, but this is not a reliable control method on its own. It’s better to focus on barriers and Bt.

Controlling pickleworms organically requires a proactive and persistant approach. By combining garden sanitation, row covers, timely applications of Bt, and encouraging natural predators, you can protect your cucurbit harvest. The key is to start early, be consistent, and not wait until you see bored fruits. With these methods, you can enjoy a healthy, productive garden without resorting to harsh chemicals. Remember, the goal is managment, not total eradication, to keep your garden in a balanced, healthy state.