The benefits of companion planting

It works in three distinct ways. It is an organic way to protect your plants from pests, it encourages pollination by butterflies, bees and insects and it can improve the performance of the plants.

Most companion plants are strongly scented and it’s this that helps their neighbours avoid infestation. The strong scents can confuse, hide or repel pests from the main crop but they can also attract the predators of the pests that you are hoping to avoid such as ladybirds and lacewings.

For example, alliums such as garlic chives smell stronger than carrots and so can disguise the whereabouts of your carrot plants from carrot root fly when the flies can normally detect the sweet smell from a mile away. The same is true of lavender and it also attracts pollinators.

Nasturtiums are as valuable as companions and are commonly grown alongside beans and cabbages. Their pretty flowers are more attractive to aphids than the beans, pollinating insects are also attracted which is great for the plants and some of these very insects eat the aphids.

There is an appealing synergy to companion planting and it is an organic way of minimising use of pesticide. That said, it is not an exact science and many people have their own successes. Below are a few of the more common combinations of companion planting to try but it is by ne means comprehensive. You may be inspired to explore new friendships between plants.

Main crop - Companion - How does it work

Asparagus - Tomatoes - Scent repels asparagus beetle

Beans- Nasturtium, marigold - Nasturtium attracts aphids, marigold repels whitefly

Brassicas - Nasturtium, sage, mint, camomile, dill, oregano, rosemary, sage - Cabbage white butterflies lay eggs on nasturtium not crop plant, herb scent confuses pests, mint deters flea beetles and ants, rosemary repels cabbage fly

Broad beans - Summer savory - Repels blackfly

Carrots - Garlic chives, spring onions, leeks, lavender, mint, rosemary - Strong scent confuses carrot root fly, disguises presence of carrots, lavender deters aphids and rosemary repels cabbage fly

Chrysanthemum - Chives - Scent deters aphids

Courgette - Marigold - Marigold flowers attract pollinators

Cucumbers - Nasturtium - Deters whitefly

Leeks - Carrots, lavender - Carrot scent deters leek moth, lavender scent confuses pests and deters aphids

Onion - Mint - Scent confuses and deters opinion fly

Onions - Carrots - Scent deters onion fly

Radish - Mint - Scent deters flea beetles

Roses - Thyme, garlic, mint, chives - Scent of herbs deters blackfly, garlic smell deters aphids

Runner beans - Sweet peas - Attract pollinators

Strawberries - Borage - Deters tomato hornworm, improve strawberries’ flavour

Sunflower - Chives - Scent deters aphids

Tomatoes - Borage, dill, mint, marigold, chives, basil - Borage and dill deter tomato hornworm, mint scent confuses pests and deters beetles and ants, marigold deters whitefly, chives deters aphids, basil deters aphids

More tips on pest avoidance

Insect and bird friendly plants throughout the plot will attract predators that eat slugs and aphids as well as pollinators.

Intercropping can help, so plant fast growing crops (e.g. lettuce) between wider rows of slower growing crops (e.g. parsips) to help prevent weeds that spread disease growing.

Avoid growing row after row of the same plant in the same area as pest can find them more easily as the scent is concentrated and it’s easier for them and for disease to devastate the crop.

===

This article first appeared in March's Smallholder magazine. For your copy subscribe or ask your local newsagent for a copy.