Squash companion planting – 7 vegetables, flowers, and herbs to repel pests and attract beneficial insects, plus bad partner plants to avoid

There is a lot of choice when it comes to growing squash. That includes picking from the many varieties, with different shapes, sizes, and colors, deciding whether to grow in the ground or containers, and whether to let plants sprawl or train them to grow vertically.

No matter which, where, and how you choose to grow squash, you want your plants to grow strongly and produce a great crop of fruits to pick. That is where squash companion planting can help.

There is a good selection of vegetables, herbs, and flowers that will ensure your squash plants develop healthily and reduce the risk of pest problems, helping you get a great harvest. This guide looks at some of the best plants for squash companion planting and reveals others that do not make good partners.

7 of the best for squash companion planting

The following vegetables, flowers, and herbs are all fantastic partners for squash companion planting:

1. Beans

Beans and squash form two-thirds of the most famous example of companion planting, the 'Three Sisters'. The third crop is corn, with all three vegetables benefiting each other in this historic planting system.

Beans and squash companion planting is beneficial as the beans fix nitrogen in the soil and make it available for the squash plants. The beans enrich the soil and give the squash a readily available nitrogen source throughout the growing season.

Pole beans, such as runner beans or climbing forms of French beans, are preferable as they will grow vertically in a different space from the squash. Planting bush beans means the two crops compete for space, and harvesting can be trickier.

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2. Corn

It would be amiss of me to discuss squash companion planting without including the other crop from the famed 'Three Sisters'.

Growing corn in that system primarily supports the growth of the beans, which can climb the strong stalks of the corn plants, however, it also offers positives to the squash in the form of shade from strong winter sun.

While the large sprawling vines and foliage of the squash plants shade the roots of the corn and the beans, the squash itself gets some relief from the summer rays thanks to the tall-growing corn.

Every grower needs to experiment planting corn as part of the 'Three Sisters' to see the positive effects all three crops get from this companion planting colossus.

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3. Radish

Radishes are simple and fast-growing vegetables, and a good candidate for squash companion planting as they help with pest control.

Growing radishes near squash can deter squash vine borer. These troublesome pests can feed on stems or turn squash leaves yellow, but planting radishes can reduce their numbers and stop the borers from wrecking your harvest.

As well as squash bugs, radish can also help against cucumber beetles, which target cucumbers, squash, and melons. The peppery aroma of radishes discourages the pests from laying their eggs on the squash plants.

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4. Marigold

Marigolds work for companion planting squash as they offer several benefits, including repelling pests and attracting pollinators.

Growing marigolds means you don’t just get bright and joyful blooms to enjoy, but you also benefit as the plants actively repel flies, wasps, mosquitoes, and squash bugs, as well as other vegetable garden pests like tomato hornworm and Mexican bean beetle.

Marigolds also make great trap plants for pest control, attracting thrips, slugs, and snails away from other crops. The bright annual flowers attract beneficial insects to eat pests for you, and bring pollinators to the squash flowers.

The best marigolds to plant in a vegetable garden for companion planting are French marigolds, which are smaller-growing and more pungent than the larger African marigold varieties.

One stunning example is this Strawberry Blonde French Marigold at Burpee that produces a mix of pink, rose and yellow blooms.

5. Nasturtium

Nasturtium is a great edimental plant, it looks lovely in any garden and the leaves and flowers are edible. Those two facets make it worth planting, but growing nasturtiums for pest control is highly recommended for any vegetable or kitchen garden.

Growing nasturtiums for squash companion planting is beneficial as they attract bugs away from your squash plants, including aphids or whiteflies.

Nasturtiums also repel squash bugs and cucumber beetles thanks to their distinctive spicy aroma, but will attract hoverflies, ladybugs, lacewings, and beneficial wasps to deal with pest populations.

Nasturtiums are easy flowers to grow from seed to make lots of plants around your squashes.

However, they sprawl and are best planted a safe distance (around 5-6 feet) from squash plants to prevent pests from transferring from the nasturtiums to your crops.

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6. Dill

Dill is a very versatile herb with a strong aniseed flavor. As well as getting a plentiful harvest of dill to use in the kitchen, growing the herb with squash helps to deter many potential pest problems.

The aromatic herb has a strong liquorice-like fragrance that masks the smell of the squash plants, confusing pests, including squash bugs, and deterring them from landing on the squash themselves and becoming an issue.

That aroma when growing dill does, however, attract beneficial insects. Ladybugs, lacewings, predatory wasps, and more will be tempted towards the herb and feed on pests like cucumber beetles, thrips, spider mites, whiteflies, caterpillars, and aphids to keep the squash pest-free.

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7. Borage

Borage is a lovely little herb with edible star-shaped flowers and hairy leaves. It is another flower to plant in a vegetable garden to deter pests, including slugs, snails, and squash bugs, and attract beneficial insects that eat pests and pollinate flowers.

Borage is also renowned for being a plant that improves soil quality, adding trace minerals to the soil where it grows. It means plants nearby are stronger against pests and diseases.

The borage leaves are also rich in vitamins and minerals, and older foliage makes a good mulching material to release nutrients into the soil as it decomposes.

Borage grows well in full sun or light shade, and it will self-seed prolifically around a garden. You can get borage seeds at Burpee to sow directly into the garden in spring.

5 bad companion plants for squash

All crops have good and bad potential neighbors, and it would be a companion planting mistake to have squash growing with any of the following plants:

• Melons - these are heavy feeders and will compete massively with squash for nutrients in the soil. Growing melons nearby may result in disappointing results from your squash plants.
• Cucumbers - the two crops love the same warmth, but require similar nutrients and attract the same pests. Growing cucumber next to squash increases the risk of attracting cucumber beetles or squash bugs to the plants.
• Fennel - it is an allelopathic plant that releases chemicals into the soil that actively inhibit the growth of neighboring plants. Squash is one plant you should never grow next to fennel, as it will be stunted.
• Potatoes - these are another heavy feeder that can impact plants around them as they take lots of water and nutrients out of the soil. Some crops can work as potato companion plants, however, squash is not one of them.
• Pumpkins - they may be very similar crops, but there are negatives to growing pumpkins with squash. Both vining crops need lots of space and can compete for room, water, and nutrients. Plus, some varieties of squash and pumpkin can cross-pollinate.

FAQs

Can peppers and squash be planted together?

Yes, peppers can be planted close to squash plants. The squash vines and foliage protect the roots of the peppers during hot weather and retain moisture in the soil to benefit both crops. Also, as peppers grow vertically and squash sprawl, the two won’t compete for the same space.

Are broccoli and squash companion plants?

It is not recommended to grow broccoli and squash together as companion plants. Both the vegetables are heavy feeders that will compete for water and nutrients, and broccoli plants are susceptible to many pests that can also trouble squash.

I have grown squashes for many years, as a professional kitchen gardener (where I grew them for restaurants and to sell to the public) and on my plots at home. My preferred varieties to grow are butternut squash and delicata squash, as they are both reliable and easy varieties to grow.

Companion planting comes highly recommended to keep plants pest-free, while being careful when watering will prevent diseases.

As for how to water plants, focus the water at the base of the plant. Avoid just soaking the foliage, as this can lead to fungal problems, including powdery mildew.