Gardening > Companion Planting

Companion Planting



The theory behind companion planting is that various flowers and vegetables will do better in the garden if certain plants are grown near them. This is not a new idea and is based largely on folklore and traditions, some of which have been scientifically proven.

When companion planting does work it usually depends on the companion secreting a substance that kills pests; giving off a smell which camouflages the smell of the protected plant; hiding the plant visually or attracting beneficial insects which prey on the pests that might attack it.

Some companion growing ideas to try:

1/ Plant alliums near carrots, tomatoes and lettuce. The strong smell of the allium is supposed to deter pests especially carrot fly.

2/ Asparagus secretes a substance from its roots which can kill trichodorus, a nematode responsible for damaging tomato roots.

3/ Tomatoes protect asparagus against asparagus beetle.

4/ Beans fix nitrogen in the soil making them beneficial to potatoes, cauliflower, carrots, cucumber and cabbage.

5/ Mint should be planted next to cabbages as the scent of it repels the cabbage white butterfly.

6/ Chives, when grown near carrots, are supposed to combat fungal disease. It is also said that they keep aphids away from tomatoes.

7/ Chamomile is sometimes referred to as "the plant doctor" because it seems to help sick plants recover.

8/ Chervil and dill attract aphids away from lettuce.

9/ Mexican marigolds secrete a substance which kills nematodes. Their perfume repels whitefly and they attract beneficial insects in the form of the hover fly. Thus they make good companions for most vegetables and roses.

10/ Plant nasturtiums near radishes to improve the flavour of radishes and under apple trees where they repel wooly aphid.

11/ Runner beans and sweetcorn grow well together. Let the beans scramble up the sweetcorn and the sweetcorn will benefit from the nitrogen that the beans release back into the soil.

12/ Yarrow makes a very good companion for most vegetables because it attracts many insects which enrich the soil with their remains when they die.

It has to be said that companion planting describes the way a traditional cottage garden was set out. Whether or not this form of planting evolved because it was observed that certain plants did well together or for more prosaic reasons is open to speculation. Flowers, herbs and vegetables may have been planted together for ease of harvesting or because more plants went into the pot or salad in bygone days.

The regimented rows of single vegetable planting in the urban gardens or allotments of the 19th century depended very much on the use of pesticides and fertilizers both of which have gone out of fashion. Both are deemed to be counter-productive, if not downright harmful to the soil, the environment and those who eat the produce.

For these reasons alone it is well worth trying a few of the old ideas which may just harbour some modern scientific truths.