What is Companion Planting?

The nature of companion planting in edible gardens is basically planting one or more different species of plants which benefit one another, in close proximity to each other. This also creates diversity in the garden, making it less likely for pests and diseases to spread rampantly through the vegetable garden.

For example, while the cruciferous gang of vegetables may all enjoy the same cool climate and growing conditions, they do not like to hang together in the garden because they share the same pests and disease problems, and should be planted in separated beds. However, if they are planted with good companions like Calendula, Rosemary, Sage and Thyme, these companion plants will help to deter pests with their strong scent, while attracting bees and other pollinators with their aromatic flowers.

Vegetable Companion Plants Image by congerdesign from PixabayIn subtropical regions, late summer, autumn and winter, are the most popular times to garden, and especially if you wish to grow your own vegetables. Most vegetables have definite seasons in which they prefer to grow, and because the seasons are not clearly defined in the subtropics, many crops only have short timeslots when they will thrive. Learning to pick these timeslots is the tricky part of subtropical veggie gardening. If you don’t get the timing right, your crops will either not grow at all or grow poorly, and could therefore suffer from serious pest damage.

Members can click here to read my article: "Growing vegetables in the subtropics"

What are Cruciferous Vegetables?

Cruciferous vegetables are vegetables of the family Brassicaceae or Cruciferae, a medium-sized and economically important family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. It includes many of our favourite winter vegetables like: Broccoli, Brussels Sprout, Cauliflower, Cabbage, Kale, Collard Greens, Kohlrabi, Garden Cress, Bok Choy, Mizuna, Tatsoi, Rocket, Radish, Mustard Greens, Radish, Turnip and Rutabago.

Companion Plants for Cruciferous Vegetables

The following list of companion plants is specifically for Cruciferous vegetables, although I do mention other vegetables they will protect.

Not only will these companions make your veggie patch look stunning and keep your plants healthier, it will hopefully encourage you to experiment more with companion planting in your edible garden.

Alyssum Image by May hokkaido from PixabaySweet Alyssum

Alyssum is a magnet for pollinators and also attracts beneficial insects like parasitic wasps and hoverflies. In the veggie garden it also acts like pretty living mulch that suppresses weeds.

Sweet Alyssum is excellent planted around or underneath cruciferous vegetables, and your veggie patch or pots will be so much prettier.

Members can click here to read more about Alyssum

Calendula

Calendula contains alkaloids, enzymes, etheric oils and resins, amongst other substances, making it a valuable companion plant for vegetables, herbs, strawberries and other berries to deter common pests like aphids and whitefly.

Under fruit trees it’s invaluable, as the roots of calendula emit a scent that keeps nematodes (eelworm) at bay.  Once it has finished flowering, to keep eelworm at bay, dig the entire plant into the soil as a green manure, and also to enrich the soil.

In South Africa calendula blooms heavily in winter and spring, attracting pollinators like bees, hoverflies, and ladybirds to the garden. Pop calendulas in wherever you have gaps in the winter veggie patch, they are excellent companions for cruciferous vegetables, and also lettuce, and peas.

Members can click here to read more about Calendula

Petunias Image by Hans from PixabayPetunia

Petunias make bright and cheerful companion plants for cruciferous vegetables because they act as a tonic plant, so if you do not get heavy frosts in winter try planting some nearby, your veggie patch will look much more inviting.

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Nasturtiums & Marigolds

In warmer, frost free regions annuals like nasturtiums and marigolds are the top companion plants for cruciferous vegetables because they lure hungry caterpillars away from broccoli and other brassicas.

Members can click here to read more about Nasturtiums

Members can click here to read more about Marigolds

Coriander

In subtropical gardens coriander is a favourite herb to grow in the cool seasons, as in summer it can bolt during hot weather. As a companion plant in the garden it attracts beneficial insects like hoverflies and parasitic wasps, and is very useful planted near cruciferous vegetables.

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Chives in bloom. Image by Hans Linde from PixabayChives

Chives help to deter aphids and are great near cruciferous vegetables. They are also good growing near carrots, lettuce, and beetroot.

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Onions, Spring Onions & Garlic

Because the leaves and flowers of onions and garlic have a pungent smell that naturally repels insects, they are particularly beneficial as a pest repellent in the vegetable garden in general.

They are especially good for cruciferous vegetables, helping repel cabbage caterpillars, cabbage maggots, cabbage worms, Japanese beetles, carrot fly and aphids.

Onions and garlic also repel insect pests of strawberries and peaches, and grow well close to tomatoes, repelling the red spider mites that normally favour tomato plants.

Plants from the onion family also do well with celery, beets, spinach, lettuce, parsnips, sweet peppers and carrots because onions and garlic repel insect pests that favour these vegetables.

Members can click here to read more about Onions

Members can click here to read more about Garlic

Sage' Tricolor' Image by deluna from PixabaySage

Sage loves to grow with rosemary, and makes a good companion plant for all cruciferous vegetables and also carrots because it helps to repel the cabbage moth, carrot fly, and white flies.

This shrubby evergreen perennial plant can live to be 15 to 20 years old, although for culinary and medicinal purposes the plants are usually replaced every 4 to 5 years, so plant it in the vegetable garden where it can grow undisturbed.

Sage will enhance the looks of any vegetable or flower garden with its long, velvety leaves which are a beautiful soft grey, and today many exciting new garden varieties have been developed with gorgeous leaves flushed with purple or marked in white and pink.

Members can click here to read more about Sage

Thyme

Because thyme it is highly aromatic, it helps to repel cabbage root fly, whitefly, red spider and aphid, making it a wonderful companion plant for cruciferous vegetables and also onions, eggplant, tomatoes and strawberries.

Thyme will also stimulate the growth of neighbouring plants and loves growing close to lavender, oregano, dill and mint.

Thymus species are very popular with pollinators like bees, and are easy to incorporate into the vegetable patch as there are many varieties of thyme, including groundcovers and  small border or potted plants.

Members can click here to read more about Thyme

Rosemary 'Roseus' Image by Beverly Buckley from PixabayRosemary

Rosemary is grown as a companion plant for cruciferous vegetables, beans and carrots, as it helps to deter cabbage moths, bean beetles and carrot flies. Rosemary flowers are also a favourite of honey bees and other pollinators.

Rosemary is easy to incorporate into your veggie patch as there are many forms, from prostrate groundcovers and trailing varieties, to upright forms which can reach 1 to 2m tall if left un-pruned. Because it responds well to clipping Rosemary makes a lovely low formal or informal hedging plant or screen for the vegetable garden, and the prostrate varieties make hardy groundcovers.

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Oregano & Marjoram

Oregano and Marjoram grow easily in a pot or in the ground, and are good companion plants for vegetables and roses because they attract pollinators to the garden and help to repel aphids. They are also said to repel the cucumber beetle and squash bugs.

Try planting them near to cruciferous vegetables, as well as tomatoes, peppers, and lettuce.

Members can click here to read more about Oregano and Marjoram