How to Companion Plant

Companion planting is the gardening method of growing plants together that assist each plant's growth in some way, whether it is by keeping away pests, increasing uptake of nutrients, or encouraging pollination. And a little like people, some plants prefer to keep their distance from other plants so that they grow better and aren't stunted in their potential. This article provides the basics of getting started in companion planting.


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    Understand the ways in which companion planting can help improve your gardening. There are a number of possible benefits, including:[1]
    • Flavour improvement – some plants can improve the flavor of other plants simply by being in close proximity with one another.
    • Nitrogen fixation – some plants are very good at this, helping plants less able provided they are planted in close proximity.
    • Pest control – plants that discourage certain pests and can guard plants that are normally attractive to these pests; or, the plants can attract beneficial insects that keep predators down.[2]
    • Pollination increase – some plants can attract pollinators well, and other plants close by benefit from the pollinators arrival.
    • Disrupting generic planting – a way to prevent the problems that come with monoculture growing, by having plants that differ from the monoculture crop.
    • Shelter or support – the interaction of companion plants can serve to either shelter or support other plants, including providing windbreaks, shade, and even something additional to grow on.
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    Decide on the reasons you want to use companion planting for. Once you know why you want to companion plant, you will be better placed to be able to make sound choices about the types of plants. Read through the list above to help direct your search for suitable companion plants, whether it be for pest control, shelter, crop disruption, or one of the many other reasons, or several combined.
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    Be aware that some combinations are advantageous while others are disadvantageous for plants. Some plants will grow vigorously in the presence of other plants, while others may do very poorly. For example, rue is an herb that is commonly incompatible with a range of garden plants, and pine trees tend to secrete a chemical that deters the growth of anything else under their trunk. On the other hand, basil and tomatoes are known well as a match made in heaven! Knowing the incompatibility as well as the compatibility is equally important.
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    Learn some of the more common companion plant combinations. The following table demonstrates which companion plants do well together, or which should be grown apart, along with explanations:
Plant Companion Incompatible
Alfalfa Practically pest and disease free; alfalfa is prized for its ability to fix the soil with nitrogen. It also accumulates iron, magnesium, phosphorous, and potassium. It has a long taproot that can penetrate most soils and improve them. -
Amaranth Corn and cabbage family; amaranth hosts predatory ground beetles; camouflages the odour of the cabbage family, thereby deterring predators -
Anise Coriander; anise hosts predatory wasps that consume aphids -
Apple - Black Walnut Tree, Hawthorn
Artichoke Sunflower, tarragon None
Asparagus Tomato, parsley, basil, carrots Chive, garlic, leek, onion
Basil Beans, broccoli, Brussels sprouts, cabbage, cauliflower, collard, kale, marigold, pepper (capsicum), tomato, asparagus - with tomatoes and asparagus plants, it repels flies, aphids, mites and mosquitoes and can help with tomato hornworms and asparagus beetles. Rue, sage
Beans Most vegetables and herbs, carrots, cucumber, lettuce Onions, garlic, sunflowers
Beetroot, beet Lettuce, beans (except runner beans), kohlrabi, onions, cabbage family; adds minerals to the soil and adds magnesium if composted; garlic and mint help beets to grow better -
Borage Tomatoes, strawberries; deters tomato worms, adds trace minerals to soil, increases proximate plants disease resistance, enhances flavour of strawberries, self seeds -
Broccoli Basil, beans, cucumber, dill, garlic, hyssop, lettuce, marigold, mint, nasturtium, onion, potato, radish, rosemary, sage, thyme, tomato Grapes, lettuce, rue
Cabbage family (includes broccoli, brussels sprouts, cauliflower, kale) Aromatic herbs, celery, beets, onion family, chamomile, spinach, chard Dill, strawberries, tomato, pole beans
Caraway Good next to shallow rooted crops, loosens compacted soil with deep roots, flowers attract parasitic wasps Dill, fennel
Carrots Pea, lettuce, rosemary, onion family, sage, tomato; can benefit from being grown near flax Dill, caraway, celery, parsnips
Catnip Deters mice, flea beetles, Japanese beetles, squash bugs, weevils, ants, etc.; attracts cats -
Celery Onion and cabbage families, tomato, nasturtium , beans, leek, spinach Parsnips, carrot, parsley, corn
Chamomile, German Cabbages, cucumbers, onions (improves flavour), aromatic herbs; hosts hoverflies and wasps, increases oil production from surrounding herbs and tonic for all plants it grows near -
Chives Roses; prevent mildew, deters green flies and repels aphids -
Chrysanthemums Kills bad nematodes, repels Japanese beetles (white flowers) -
Clover Grapes, apples; attracts beneficial insects, great for green manure, attracts predators of woolly apple aphid -
Comfrey Avocado, fruit trees; accumulates calcium, phosphorous and potassium; can be used as a slug trap -
Coriander Anise; deters spider mites, aphids, potato beetle -
Corn, sweetcorn Potato, beans, pea, pumpkin, cucumber, squash, climbing beans, amaranth, melons, peanuts, parsley, soybeans, sunflower, morning glory, white geranium Tomato, celery
Cucumber Beans, sweetcorn, pea, sunflowers, radish, celery, lettuce, dill, beets, carrots, nasturtium; when grown with sunflowers, the stems provide support for the cucumber vines Potato (bad both ways), aromatic herbs, sage
Eggplant Beans, marigold, garlic, pea, pepper (capsicum), potato, spinach, tarragon, thyme Fennel
Garlic Collard, raspberry, roses, apple trees, pear trees, cucumber, lettuce, celery; garlic accumulates sulphur (a naturally occurring fungicide); good against codling moths, Japanese beetles, root maggots, snails, and carrot root fly Bean, pea
Grapes Hyssop, basil, beans, peas, blackberries, chives, elms, mulberry trees; plant clover with grapes to increase soil fertility Radishes, cabbage
Horseradish Potatoes; deters potato bugs, blister beetles, and helps make potatoes more disease resistant -
Hyssop Cabbage, grapes; deters cabbage moths and flea beetles; can be used to encourage bees to return to their home (rub on the hive) Radishes
Lavender Fruit trees; flowers provide nectar, attract beneficial insects, deters whitefly and codling moth -
Leek Carrot; can repel the carrot fly Legumes
Lettuce Carrot, radish, strawberry, cucumber, spring onions (scallions), marigolds, beans, collards Broccoli, fava bean, grains
Marigolds (Calendula) A major pest deterrent: Keeps soil free of nematodes; discourages many insects. Plant freely throughout garden; known as the "workhorse of pest deterrents"[3] Deters whiteflies. French marigold is less potent than Mexican marigold Be careful using Mexican marigold near cabbages and beans as it can have a herbicidal effect; avoid planting marigolds next to beans at all
Marjoram Improves flavour of all vegetables and many herbs -
Melons Corn, nasturtium, radish; oregano protects it from pests Potato
Mint Cabbage and tomatoes; deters white cabbage moths Very invasive once starts growing, can crowd out other plants
Nasturtiums Tomatoes, cabbage, cucumbers, and under fruit trees; deters wooly aphids, whiteflies, squash bug, cucumber beetles and other pests of the cucurbit family; attracts predatory insects Radishes, cauliflower
Onion family Beets, carrot, lettuce, cabbage family, summer savory, cauliflower, celery, chamomile, collard, cucumber, dill, kale, pepper (capsicum), potato, radish, rose, squash, strawberry, tomato; inter-crop with leeks and carrots to confuse carrot and onion flies; onions with strawberries help protect strawberries from disease Beans, peas, asparagus, gladiolus
Oregano Beans - enhances flavour; cabbage, broccoli, cauliflower, cucumbers, grapes -
Parsley Tomato, asparagus, rose Mint
Pea Carrots, radish, turnip, cucumber, corn, beans; peas fix nitrogen in the soil Onion family, gladiolus, potato
Pennyroyal Brussel sprouts, broccoli, cabbage; deters ants, aphids, ticks, fleas, and cabbage maggots Poisonous to cats, do not plant where cats can access it
Pepper Bean, carrot, marigold, marjoram, onion family, tansy, tomato -
Petunias Tomatoes and everywhere; repel asparagus beetle, leafhoppers, some aphids, Mexican bean beetles, tomato worms, other garden pests -
Potato Beans, corn, cabbage family, marigolds, horseradish; horseradish planted at the edges will of a potato patch will provide overall protection; comfrey will help protect from scab Pumpkin, squash, tomato, cucumber, sunflower, fennel, kohlrabi, melon family, parsnip, swede/rutabaga, turnip; tomatoes can transfer blight
Pumpkins Corn, melon, squash, marigold (deters beetles), nasturtium (deters bugs, beetles), oregano good overall pest protection Potato
Radish Pea, nasturtium, lettuce, cucumber, beans, cabbage family, carrot, chervil, collard, grapes, melon family, onion family, squash Hyssop
Rhubarb Cabbage family, beans (protects from black fly), columbine flowers, onion family, garlic, roses; deters red spider mite from columbines -
Rosemary Cabbage, beans, carrots and sage. Deters cabbage moths, bean beetles, and carrot flies -
Rue Roses, fruit, figs, raspberries (deters Japanese beetle), lavender. Cucumber, cabbage, basil, sage
Sage Cabbage, carrots, rosemary; repels cabbage moths, carrot flies, and ticks Cucumber, rue, onion family
Southernwood Cabbage, garden in general, virtually pest free but watch its crazy growth -
Spinach Strawberry, fava bean, beans, peas -
Squash Nasturtium, corn, marigold Potato
Strawberry Borage, beans, lettuce, onion, sage, spinach, thyme Cabbage, broccoli, Brussels sprouts, cauliflower, kohlrabi
Summer savory Onions, garlic, beans; enhances flavour of beans, onions, and protects from bean beetle; loved by honey bees -
Sunflower Beans, corn, squash; attracts hummingbirds which eat whiteflies; great as decoys for aphids away from corn Potato
Tansy Fruit trees, roses and raspberries. Deters flying insects, Japanese beetles, striped cucumber beetles, squash bugs, mice, and ants; can be invasive and is toxic for livestock -
Tarragon Plant throughout garden; few pests like it! -
Thyme Cabbage; repels cabbage worms, flea beetles, whitefly, and cabbage maggots -
Tomato Onion family, nasturtium, marigold, asparagus, carrot, parsley, cucumber; basil improves flavour, growth and repels flies and mosquitoes Potato, fennel, cabbage family, apricot, dill, black walnut tree (walnut wilt), corn (attacked by same worm), pole bean, kohlrabi
Turnip Pea, onion family Potato
Wormwood Deters animals when planted as a border; deters black flea beetles, cabbage worm butterflies. Peas, beans
Yarrow Plant near aromatic herbs to increase production of essential oils; has natural insect repelling properties and is great for compost (speeds up break-down) -


  • Aromatic herbs include: basil, thyme, oregano, chamomile, hyssop, mint, rosemary, sage, etc.
  • Even with the knowledge that some plants benefit one another well, local conditions, soils, temperatures, etc., may impact on the extent of the effects. It is important to keep trying and observing to work out which combinations of companion plants work best.
  • For plants that benefit from invasive growers such as mint, try using the clippings as mulch rather than crowding out the plants.


  • This is a guide. It is not foolproof and it is prudent for you to work out by trial and error what works for your own garden space. Some of the ideas may work, some may not, some may work differently from what you expect but give it a go and it's likely that you will be pleasantly surprised at the results gleaned from centuries of gardeners, farmers, and horticulturalists observing and sharing on this knowledge.

Things You'll Need

  • Companion plants
  • A plan with what you need from your companion planting

Article Info

Categories: Planting and Growing