Companion planting

Your plants will grow much better with a little help from their friends.

By Lee Ann Bramwell

When I first started growing vegetables, I was always lamenting the fact that gone-to-seed cauliflowers, skyscraper lettuces, and a healthy population of slugs did not an appealing picture make.

So, of all gardeners, I was probably the most delighted when mixing vegetables and ornamental plants became the Next Big Thing. Now, it’s not just trendy, but almost compulsory.

Companion planting has actually been around for centuries. And while it is certainly a good way of bringing colour and variety into the same space, the European and Asian peasant gardeners of the 17th century probably weren’t thinking
about how pretty orange flowers would look amongst the lettuces when they planted marigolds. It’s more likely they were following the principle of the three Ps of companion planting: pest control, pollination and productivity.

Put borage alongside strawberries – they love each other’s company.
Put borage alongside strawberries – they love each other’s company.

While companion planting has a long history, the mechanisms have not always been totally understood. In most cases, they are formed out of oral tradition, family secrets, front porch recommendations and urban myth. Despite historical observation and horticultural science, companion planting is practised because it’s a functional method of planting, that allows veggies and herbs to grow to their maximum potential.

Properly chosen plants support each other by making more efficient use of the soil, repelling insects and inhibiting the spread of viruses and bacteria. By planting them close together, the soil becomes shaded from the sun, and that helps to keep weeds down and moisture in. Some plants will encourage bees and therefore enhance pollination, and taking care of the garden’s eco-system promotes increased productivity.

Of course, learning who gets on with what will keep you as busy as figuring out the romantic preferences of a gaggle of 15-year-olds, but on the upside, at least plants don’t tend to change their minds about who they like. So, once you’ve got the list, you can create a vegetable garden full of happy marriages.

Basil and tomato are best friends  in the garden and on the plate.
Basil and tomato are best friends in the garden and on the plate.

One of the things I find most interesting about companion planting is that plants that like each other tend to look good together. Strawberries like to cuddle up with borage, and the red and blue colours are pretty good together. As an added extra, bees love borage and, while they’re visiting, they’ll also pollinate your berry flowers. Perfect. Chives, lettuce and spinach also go well planted near strawberries, and there are no colour clashes there.

I’m assuming everyone knows that tomatoes and basil are best friends, not only on the table, but also in the garden. What might not be so well known is that feverfew is also a good addition to the tomato patch. Its long-lasting white flowers are an appealing contrast to the tomatoes and, again, bees and butterflies will be attracted. Feverfew is also good for repelling moths and whitefly. When you’re pottering around the vege garden, grab a few leaves, tear them up and scatter them on the ground.

If you have plenty of room, plant cucurbits like pumpkin, cucumber and zucchini together, and add nasturtium. You’ll end up with a mad mess of orange and yellow, truckloads of foliage, and runners that look like they’re heading for China. But you should get plenty of cukes and zukes, as well as pretty orange blooms for your salads.

Try it out first

If you find the idea of companion planting a bit hard to swallow, you’re not alone. There are plenty of scientific minds who agree with you. For the sceptical, try testing some of the popular companion recommendations in your vege garden. Try growing one lot of peas with good companions of beans, carrots and corn, another lot with bad companions of onion and garlic, and a third lot with nothing. And if you have two plants of the same rose, grow garlic under one of them for a season, and nothing under the other. You could count the aphids on each plant, but chances are you can form an opinion just by noting whether there is a significant difference.

Old-fashioned flowers

Plants like dahlias and gladioli are back on the hot list. You can plant dahlia corms until the end of the month. Plant 5-6cm deep, 50cm apart, in well-drained soil in full sun. Fertilise well when planting, and again with liquid fertiliser when flowering. Plant gladioli from now till about December. Plant 8-10cm deep and 15cm apart in a sheltered position with full sun and good drainage. They’ll flower about three months after planting, so stagger them to get a continuous display.
Use minimal fertiliser,but adequate water.

Did you know?

• Some plants have shapes which confuse the pest’s recognition ability.

• The scent of the volatile oils in some companion plants discourages certain pests.

• Nitrogen-fixing plants of the legume family supply nitrogen to other plants.

• Some plants will attract insects that kill pests, as well as birds and insects that spread seeds.

• Horseradish increases the potatoes’ disease resistance.

• Some plants enhance each other’s growth by physical and energetic means. Evidently, they just enjoy being together

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