Companion Gardening and Pests

It takes more than good sun, soil and nutrients to ensure success in the garden. Companion planting is something every gardener can easily incorporate for a fruitful season.

Time-honoured garden wisdom says certain plants, when grown together, increase each other’s health and yield.

By planting different plants together, you get the benefits of attracting pollinators, deterring pests, mulch/weed control, providing necessary nutrients to the soil, and more.

Additionally, plants that require the same nutrients are their neighbours may struggle to get enough for themselves and thus have poor health and yield.

Probably the most well-known companion gardening trio is the Three Sisters; peas, squash and corn.

The peas provide nitrogen to the plants, the corn gives the peas a place to grow up, and the squash acts as a ground cover to keep the soil moist, cool, and free of weeds.

BENEFITS OF COMPANION PLANTING

Shade regulation: large plants provide shade for smaller plants in need of sun protection, like cucumbers and lettuce.

Natural supports: tall plants like corn and sunflowers can provide a growing trellis for things such as cucumbers and peas.

Improved plant health: when one plant uses certain nutrients from the soil, it changes the make up in the soil which can benefit nearby plants

Healthy soil: some plants like peas and beans provide nitrogen back into the soil. Similarly, plants with long taproots like burdock, bring up nutrients from deep in the soil, enriching the top soil to the benefit of shallow rooted plants.

Weed suppression: planting sprawling crops like squash with upright plants minimizes open areas where weeds take hold.

For seed starting schedules and tips, check out How to Start Garden Seeds Indoors

So, what plants are best companions? What should you not plant together? What plants help deter pests and attract beneficial insects?

Companion Plants

Plant	Really likes to be with…	Doesn’t like to be with…
Asparagus	Basil, tomato, nasturtium, parsley, borage	Onion, garlic, potato
Beans	Carrot, cabbage, cauliflower, cucumber, marigold, potato	Chives, leek, garlic
Broad Beans	Brassica, carrot, celery, corn, lettuce, potato	Fennel
Beets	Brassica, lettuce, onion, sage	Bean (pole)
Broccoli	Celery, chamomile, dill, rosemary, tansy, rosemary, onions, lavender, mint	Oregano, strawberry
Brussel sprouts	Potato, thyme	Strawberry
Cabbage	Beetroot, potato, oregano, sage, tansy, rosemary, celery, onion, mint, lavender, nasturtiums	Strawberry, tomato
Carrot	Bush beans, pole beans, lettuce, onion, pea, radish, tomato, leeks	Chives, dill, parsnip
Cauliflower	Beans, celery, oregano, tansy, rosemary, celery, onions, lavender, mint	Nasturtium, peas, potato, strawberry, tomato
Celery	Cabbage, leek, onion, spinach, tomato	Parsnip, potato
Corn	Bean, cucumber, melon, pea, pumpkin, potato, radish, pigweed	Tomato
Cucumber	Bean, celery, lettuce, pea, radish, onion, carrot, nasturtiums	Cauliflower, potato, basil
Eggplant	Bean, capsicum, potato, spinach
Leek	Carrot, celery, strawberry, onion
Lettuce	Carrots, radish, strawberry, chives, garlic, peas, cucumber	Beans, beetroot, parsley
Melon	Corn, radish	Potato
Onion	Bean sprout, broccoli, cabbage, lettuce, strawberry, tomato, radish, celery, carrot, pigweed	Bean, pea
Pea	Beans, carrot, corn, cucumber, radish, lettuce, chives, garlic, plant everywhere (increases nitrogen)	Onion family
Potato	Bean, corn, pea, eggplant, pigweed	Cucumber, pumpkin, squash, sunflower, cabbage, cauliflower
Pumpkin	Corn	Potato
Spinach	Celery, cauliflower, eggplant
Tomato	Asparagus, celery, carrot, parsley, marigold, borage, nasturtiums, dill, basil	Corn, fennel, potato
Zucchini	Nasturtium
Kohlrabi	Tansy, rosemary, celery, onions, lavender, mint
Grapes	Geranium
Parsnips	Bush beans, peppers, [potatoes, peas, radish, garlic, onions	Carrots, celery, caraway
Chives + Nasturtiums	Around fruit trees
Garlic	Plant everywhere	Beans, peas
Marigolds	Plant everywhere

Struggling to grow? Check out The Foolproof Way to Grow a Garden.

Planting for Pest Control

Some plants, especially herbs, can help deter pests. They mask the smell of the intended plant, thereby acting as a natural insect repellent.

For example, nasturtiums are so favoured by aphids that the devastating insects will flock to them instead of other plants. You might be able to grow cabbage!

Dill and basil around tomatoes – tomato hornworms

Sage around cabbage – cabbage moths

Marigolds are gold – repel nematodes which attack vegetable roots, especially tomatoes

Carrots, dill, parsley, parsnip attract beneficial insects – praying mantises, ladybugs, spiders that dine on insect pests

Lettuce, radish, other quick growing plants planted between hills of squash will mature and be harvested long before those vines need more room

Leafy greens like spinach and swiss chard like growing in the shadow of corn.

Bush beans like the dappled shade of corn and since their roots don’t go as deep, they don’t compete for water a nutrients.

Tansy discourages cutworm which attacks asparagus, bean, cabbage, carrot, celery, corn, lettuce, pea, pepper, potato, and tomato plants

Catnip, hyssop, rosemary and sage deter cabbage moth which feeds on brassica, kale, turnip and radish.

Mint wards of cabbage moth and ants.

Thyme thwarts cabbage worms, which eat brassica, brussel sprouts, collard, horseradish, kale and kohlrabi.

Lavender is great for fruit trees.

Zinnas attracts ladybugs so when planted near cabbage, the ladybugs help control the population of cabbage flies.

One of the keys to a successful garden is observation. Record your combinations and the results for year to year and share them with others! Companionship is just as important for plants as it is for gardeners!