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Companion planting
Through companion planting we can grow plants close together and enjoy the mutual benefits they bring each other.
  • An environmentally friendly, chemical-free way of gardening. Feel good knowing you are supporting wildlife as well as your plants
  • The opportunity to keep learning about plants, understanding how different types can support each other
  • Many of the plants you might choose for companion planting add colour and interest to the garden
Sweetcorn plants
Sweetcorn growing on the plant

The idea of companion planting has been known about for thousands of years. The ‘three sisters’ method for planting was used by Native Americans more than 3000 years ago. Through it, squash, beans and sweetcorn were planted in the same bed. The squash covered the ground and prevented weed growth, the beans fed the soil with extra nitrogen and the sweetcorn gave the beans a structure to climb up.

The name ‘three sisters’ came from the idea that the plants supported each other, like sisters do. This is really at the heart of companion planting. It is the idea that some plants create mutual benefits when planted close together, such as:

  • Improving the health of other plants
  • Improving the yield from crops
  • Deterring pests

When growing food crops in particular, people often think in advance about companion planting.

A small pot of basil
A small pot of basil

Some plants can pass on positive benefits to those they are near.

  • Pea-family plants such as lupins, beans, peas, and sweet peas benefit the soil as they take nitrogen from the air and store it in their roots. Beans are generally suggested as a companion for many leafy nitrogen loving vegetables such as cucumbers, corn, and broccoli.
  • Plant leeks with carrots, celery, onions and spinach for improved growth. But, steer clear of planting them near beans and peas. The leeks will benefit the other veg by repelling carrot root fly.
  • Potatoes thrive when planted near marigolds, cabbage, and beans because they improve the growth and taste. However, keep them away from cucumbers and squash because they can become more susceptible to blight.
  • Grow the best onions by growing carrots, lettuce, and cabbage nearby. Avoid planting beans and peas nearby because onions release a chemical that can inhibit nitrogen production by the beans and peas.
  • Basil is thought to improve the flavour of plants it is planted next to. This includes tomatoes, aubergines and lettuce
  • Plant tomatoes next to carrots. The hungry tomatoes can take many of the nutrients away from the carrots next to them. The carrots will root further down into the soil, resulting in a better carrot crop. This also breaks up the soil for the tomato, so the tomato roots can grow fuller, resulting in more tomatoes.
  • Sweetcorn and pumpkins. It’s not always a good idea to have tall crops next to short ones as they can create shade. Pumpkins and sweetcorn make good companions. They get the same amount of light as they first grow. In time, as the pumpkin matures, the shade from the sweetcorn is a benefit
  • Sweetcorn and lettuce or spinach. Another match where the shade from the sweetcorn is helpful. It can stop the lettuce and spinach ‘bolting’ (quickly going to seed, meaning they are no longer of use for eating)
Companion planting nasturiums
Bright nasturtiums that can attract pollinators

One way to support plant growth is through good pollination. Bees, butterflies and other pollinators are so important - without them, many of our food crops would not be able to grow. You could try these:

  • Nasturtiums, thyme, oregano, rosemary, basil and cosmos all attract pollinators to your vegetable plot
  • Poached egg plants work well planted around the base of soft fruit plants such as raspberries and blackberries
  • Sweet peas can encourage insects towards climbing beans if they are planted among them
  • Lavender is a great plant to attract pollinators. Plant it next to leeks and carrots to confuse aphids
Marigold orange flower
Bright marigolds planted to deter aphids and white fly

Some companion plants have qualities that allow them to deter pests naturally.

  • Onions or garlic chives are known to repel carrot root fly. When planting carrots and onions together, make sure there is plenty of space for the carrots' roots to grow
  • Marigolds can ward off white fly from cucumbers and aphids from runner beans with their scent. They can also help attract slugs away from sprouts. When the slugs head for the marigolds, you can follow their trial and physically remove them. Marigolds also bring bright colour to the garden
  • Tansy deters ants and other pests. It also encourages ladybirds and honeybees. Be aware it is toxic and that it can cause allergies to flare up in some people
  • Mint, oregano, parsley and thyme can drive away aphids with their strong smells. Mint can spread out of control – you may want to plant it in a pot alongside rows of vegetables
  • Nasturtiums are what’s known as a ‘sacrificial crop’. Pests such as slugs and cabbage white butterflies will be attracted to the nasturtiums and hopefully leave your cabbages, other brassicas, turnips and swedes alone. The flowers are also edible
  • Basil works in a similar way to nasturtiums but on a smaller scale. Grow in a greenhouse to draw whitefly away from early growing cucumbers and tomatoes

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