The Best Companion Plants for Summer (and What to Avoid)

Companion planting involves strategically designing your garden so that plants have good neighbors that can benefit each other’s growth and survival. Factors to consider include similar care needs, pest-fighting capabilities and pollinator attraction. For instance, marigolds are a companion for many vegetables because they have powerful pest-repelling properties. Meanwhile, pairing potatoes and tomatoes is a bad idea since these two plants are susceptible to the same diseases. Here is a roundup of some of the best companion plants (and worst) for a handful of summer crops.

See more: Companion Planting 101

Tomatoes

Nothing says summer like tomatoes. One of the best companion plants to grow next to these juicy red fruits are peppers since the two share many of the same care requirements. Growing similar plants together will help you save time and energy by getting them on the same watering and care schedule. Another handy companion plant for tomatoes is the marigold because its strong smell helps repel pests like whiteflies. Plus, their flowers will add a pop of color to your garden. Other great companions for tomatoes include sage and calendula, which both keep pests at bay.

Not every plant is a friend to tomatoes. Although peppers can be good companions, they’re also susceptible to early and late blight, which can endanger your tomato crop. Potatoes and eggplants are two other nightshades that often suffer from this disease. Meanwhile, sweet corn attracts corn earworm, which is the same pest as tomato fruit worm – and it’s not a great idea to grow plants susceptible to the same pests next to each other. Rosemary is also a no-go, as it depletes the soil of the nutrients that tomatoes need to grow.

Cucumbers

What’s a summer salad without some crisp cucumber slices? Tomatoes are one possible companion plant for cucumbers, as the two share the same sun and watering requirements. However, both of these crops are susceptible to cucumber mosaic virus and phytophthora blight and they can spread from one to the other. If you decide to grow the two together, it’s best to use tomato transplants instead of growing from seed.

Corn is an excellent companion for cucumbers, as its tall stalks can help provide support for cucumber vines. Plus, cucumbers can benefit from the shade that corn plants offer. Other friends to cucumbers include sunflowers, which attract pollinators, and dill, which can repel pests.

Meanwhile, some plants just don’t mix well with cucumbers. These include herbs like sage and mint, which can affect the taste of your cucumbers. Basil, another herb, competes for the same nutrients as cucumbers. Potatoes aren’t a great choice either, as they are susceptible to some of the same diseases and pests as cucumbers, thereby increasing the risk of an infestation. Skip big melons like watermelon and cantaloupe as well, as they are both heavy feeders that may compete with your cucumbers for space and nutrients.

Zucchini

Zucchini grows quickly and can provide you with a bountiful harvest, especially with the assistance of some summer companion plants. One friend to zucchini is oregano – its fragrance does double duty, keeping pests away and enhancing your zucchini’s flavor. Marigolds are another companion plant that can deter pests because of their heavy aroma. Beans can also benefit your zucchini harvest by helping to fix nitrogen into the soil. This can help you grow larger and greater quantities of zucchini.

Like the other foods on this list, zucchini has its foes. One of these is cucumbers, as the vines could become entangled and choke each other. The same concept applies to other types of squash, which can cause the same problem when planted too close to zucchini. Potatoes are also bad neighbors to zucchini, as they compete for the same nutrients and are susceptible to the same diseases.

See more: 7 Tips for Growing Great Zucchini Plants This Summer

Eggplants

Eggplants are the queens of summer, as they thrive in warm soil. And a number of summer companion plants can help protect your eggplant crop from foes in the garden. These include marigolds, which deter several common eggplant pests like nematodes. Meanwhile, dill can attract parasitic wasps that prey on eggplant foes like armyworms. Other plants, like borage, can help attract pollinators to your garden, which will increase your eggplant pollination rates and harvest.

Eggplants are heavy feeders, so you’ll want to avoid planting them with other heavy feeders like corn, melons or any type of squash. You should also avoid planting them with geraniums, which sometimes carry pathogens that can stunt eggplant growth.

Bell Peppers

One of the best companion plants for the bell pepper is basil, as the two share similar growth habits and a love for heat and sunshine. Basil’s strong fragrance also helps to repel pests like aphids, hornworms and whiteflies. Plus, it attracts beneficial pollinators. Borage is another great neighbor for your bell pepper crop. This flowering plant pulls minerals and micronutrients from deep in the soil up to the surface, making them available for your peppers. Marigolds shine once again as a pest-repelling plant, keeping whiteflies, aphids and other damaging bugs away. Hot peppers are another great option, as they have the same growing requirements.

There are some plants that do not do as well with bell peppers, however. These include brassicas like broccoli, cauliflower and kale because they require completely different soil acidity levels and can deter pepper growth. Plus, beans and fennel should be avoided since they can both steal nutrients that your peppers need to survive.

See more: How to Grow Bell Peppers in Your Summer Garden

Asparagus 

Last on the list is asparagus. Tomatoes do well next to this veggie because they repel asparagus beetles. Basil and parsley also stave off these pesky asparagus pests while also attracting beneficial pollinators. Other herbs that work well with asparagus include coriander, comfrey and dill, which do a good job of repelling spider mites and aphids. Again, marigolds are a great pairing because of their insect-repelling superpowers.

Meanwhile, you’ll want to avoid growing potatoes near your asparagus, as the two can compete with each other. Plus, asparagus stunts the growth of potatoes. On the other hand, alliums like leeks, garlic and onions limit asparagus’ growing capabilities.