a quick guide
Avoiding harmful chemicals is an easy way for gardeners to be nature-friendly. Companion planting is an organic alternative that could help to boost crops
For vegetable gardeners, maximising crop yield is often a priority – and for many, it's important to achieve this without the use of chemical fertilisers or pesticides.
Companion planting – growing certain plants together to boost plant health and deter pests – is one method that organic gardeners can use to improve harvests while maintaining a balanced, healthy ecosystem.
This can work in three different ways.
Making space for some flowers within the kitchen garden can create a magnet for beneficial insects.
Bees, bumblebees, butterflies, hoverflies and moths are all important for pollinating many edible crops, and some fruit and veg – such as tomatoes, strawberries and apples – are particularly reliant on our six-legged friends.
In fact, around 80 per cent of all food crops need some sort of pollination, so getting those beneficial insects buzzing around your vegetable patch could really pay dividends come harvest time.
To attract these helpful insects to your plot, grow nectar-rich blooms that pollinators love. Try sowing a few annual seeds amongst your crops: cornflowers or cosmos, for example. Sunflowers are bee-friendly too – and in autumn the seed heads attract birds such as goldfinches.
Herbs are brilliant for attracting bees and look quite at home in a potager-style garden. They're easy to grow, and many produce flowers that attract bees – rosemary and thyme, for example.
Attracting certain insects can help with pest control, as well as pollination.
For example, the larvae of hoverflies feed on aphids. Hoverflies like French marigolds. So by planting a few marigolds around your tomatoes, you can attract hoverflies and help to protect your crop. The scent of French marigolds repels whitefly too, giving your tomatoes another line of defence.
Lacewings and ladybirds eat pests too – grow yarrow, dill or coriander to encourage them to visit your plot.
As well as attracting beneficial insects to your plot, some flowers and plants will keep pests at bay.
Planting certain vegetables alongside each is one way to achieve this. Onions or leeks planted alongside carrots can help to prevent carrot fly attacks – and in return, the scent of carrots repels onion fly and leek moth.
Chives, coriander and other strong-smelling herbs can deter pests such as aphids, so can help keep aphids and whitefly away from tomatoes and other vulnerable crops
You could also try growing a 'sacrificial' crop such as nasturtiums. Cabbage white butterflies like to lay their eggs on brassica plants – but they're quite fond of nasturtiums too. So planting nasturtiums near cabbages may distract the butterflies, and keep them off the crop.
Does it work?
As with many garden practices, opinion is divided – but many people believe that companion gardening is one way to help ensure a bumper harvest.
Using companion planting alongside other methods – for example crop rotation and physical barriers such as insect netting – can help keep your plants healthy and pest-free without having to rely on chemical alternatives.
The level of success you have will depend on the conditions in your garden. In our garden, for example, carrot fly is a particular problem, and we've never had much luck growing carrots – even inter-planting with spring onions doesn't keep the pests away.
But we always plant lots of flowers in amongst the vegetables. We often see bumblebees methodically visiting every bloom on a wigwam of sweet peas, and then going on to pollinate the French beans planted alongside.
So why not try it, and see what happens in your own garden? Even if companion planting doesn't increase your crop yield, you'll be helping our struggling pollinators by providing a much-needed source of food – and, with all those colourful blooms, your kitchen garden will look lovely!
Here are eight companion plants to try.
Easy to grow from seed, the pretty pastel-coloured flowers smell gorgeous and attract bees and butterflies. Grow a wigwam of them alongside peas and beans.
Poached egg plant
Cheerful yellow and white blooms that attract pollinators, especially hoverflies. Ladybirds like it too, and both these insects feed on aphids.
The strong smell of mint can deter some pests. Grow alongside carrots, onions and tomatoes. Mint can be invasive, so it's best grown in a pot sunk into the soil.
A beautifully scented, evergreen plant that will attract bees and butterflies, while deterring aphids. Compact varieties are good planted as a hedge to border the vegetable plot
Grow these orange and yellow flowers near beans and tomatoes to keep aphids and whitefly at bay. Beneficial insects such as ladybirds and lacewings love calendula too, offering even more defence against aphids.
A strongly scented herb that can deter pests, good planted alongside cabbages and kale. Produces blue flowers that attract pollinators
Photo by on Unsplash
An excellent bee-friendly plant, that will also attract butterflies and hoverflies. Borage has the added advantage of edible flowers that look great in a salad or frozen into ice cubes to add to summer drinks.
An easy-to-grow herb with a strong citrus smell that deters pests. The summer flowers attract pollinators. It's a member of the mint family, so grow it in a pot to prevent it taking over your garden.
Little Green Space June 2021
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