A thriving garden is rarely made up of plants growing in isolation. Look closely at a cottage garden, productive kitchen garden or vegetable plot and you’ll often find flowers, herbs, fruit and vegetables growing side by side.
Companion planting takes inspiration from this diversity. By choosing plants that can grow happily together, you can make better use of space, attract pollinators and other beneficial insects, cover bare soil and create a garden that’s alive with colour and interest.
There are plenty of traditional claims about particular plants protecting their neighbours from pests or improving their flavour. Not all of these are supported by evidence, so rather than thinking of companion planting as a collection of rules, it’s more useful to see it as a way of creating a varied and resilient growing space.
What is companion planting?
Companion planting simply means growing different plants together because their characteristics complement one another.
That might mean growing a tall crop alongside a lower-growing one, combining plants with different rooting depths or adding nectar-rich flowers to a vegetable bed to encourage pollinating insects.
Some combinations can also make clever use of the available space. A quick-growing crop such as radish, for example, can be harvested before a slower-growing neighbouring plant needs the room.
The result is a garden with more variety – both above and below the soil.
Attract pollinators and beneficial insects
One of the most useful reasons for growing flowers among fruit and vegetables is to attract insects.
Bees, hoverflies, butterflies and other pollinators are drawn to nectar- and pollen-rich flowers. Many crops, including courgettes, runner beans, apples and strawberries, depend on or benefit from insect pollination.
Other visitors can help gardeners in a different way. Hoverfly larvae, ladybirds and lacewing larvae feed on aphids, while predatory insects can form part of the natural balance of a healthy garden.
Try growing a mixture of flowers with different shapes and flowering periods so that there’s something available for insects over as much of the growing season as possible.
Herbs, flowers and vegetables together
There’s no reason for herbs and flowers to be confined to separate parts of the garden.
Allowing some herbs to flower can provide an excellent source of nectar for insects, while flowering plants woven through a vegetable plot add colour as well as biodiversity.
Nasturtiums, calendula and borage are popular choices for productive gardens, while flowering herbs such as thyme, oregano, chives and dill can be particularly attractive to insects.
Think about the conditions each plant needs before putting them together. A sun-loving Mediterranean herb that prefers dry, free-draining soil won’t necessarily make the ideal neighbour for a thirsty vegetable simply because they’re traditionally described as companion plants.
The best companions are, first and foremost, plants that are happy growing in similar conditions.
Make the most of your growing space
Companion growing can be particularly useful in smaller gardens.
Instead of planting a bed with a single crop, try combining plants with different heights, habits and harvesting times. Lettuce and other leafy crops can make use of space around taller plants, while quick-growing crops can be harvested before slower ones fill out.
Climbing crops make use of vertical space, leaving the ground beneath available for suitable lower-growing plants.
This approach is sometimes called intercropping. As well as helping you make more productive use of a bed, a mixture of plants can create a much more interesting garden.
Keep the soil covered
Bare soil loses moisture more readily and provides opportunities for weeds to establish.
Where appropriate, lower-growing plants can act as living ground cover around taller crops, helping shade the soil surface. Organic mulches can perform a similar job while gradually adding organic matter to the soil.
Legumes such as peas and beans have an association with bacteria that fix nitrogen in nodules on their roots. However, it’s worth being cautious about the often-repeated claim that simply planting beans next to another crop will automatically ‘feed’ it with nitrogen. Much of that nitrogen remains associated with the legume while it’s growing.
Healthy soil comes from a combination of good gardening practices, including adding organic matter, avoiding unnecessary disturbance and growing a diversity of plants.
Don’t rely on companion planting for pest control
You may have heard that planting certain strongly scented herbs or flowers will keep particular pests away.
Some plant combinations may influence the behaviour of insects, and researchers continue to investigate how mixed planting can help with pest management. But companion planting isn’t a guaranteed barrier against slugs, aphids, caterpillars or other garden visitors.
A better approach is to encourage diversity throughout the garden.
Provide flowers for beneficial insects, create habitats for wildlife, keep plants healthy and check crops regularly so that problems can be spotted early. Avoiding unnecessary pesticide use also helps protect the predators and pollinators that contribute to the garden’s natural balance.
Try succession planting
Companion gardening isn’t only about what grows next to what – timing can be just as useful.
Succession planting means sowing or planting crops at intervals, or replacing one crop with another after it’s harvested.
Fast-growing salad leaves, radishes and other quick crops can be fitted around vegetables that take longer to mature. Once early crops have been harvested, their space can be used for something that will provide a crop later in the year.
It’s a simple way to keep a productive garden growing for longer without needing more ground.
Observe what works in your garden
Perhaps the most enjoyable part of companion planting is experimentation.
Every garden is different. Soil, sunlight, rainfall, shelter and the wildlife already present will all influence what thrives.
Try a few combinations rather than changing everything at once. Notice which flowers attract the greatest number of insects, which vegetables grow comfortably together and where plants compete for light, water or space.
Keep what works, change what doesn’t and allow the garden to teach you.
Companion planting isn’t about discovering a secret combination of plants that will solve every gardening problem. It’s about embracing diversity and creating a growing space in which plants, insects and other wildlife can coexist.
And when a vegetable plot hums with bees, spills over with flowers and provides something delicious to bring into the kitchen, growing together starts to make very good sense.
Further Reading: My Garden Journal & Notes
