Image: Martine at http://www.banlieusardises.com/

If something is chomping your carrots or munching your mizuna, don’t reach out for the pesticide. There are plants at hand which are much better at protecting your fruit and veg than harmful chemical sprays. Companion planting is one of the organic gardener’s weapons in the fight against pests, and it makes your plot look pretty as well.

Best of friends
Some plants work well together. They give off scents which distract pests from your precious vegetables, repel unwanted visitors, or improve the soil quality. Below is a list of just some helpful planting combinations:
Alliums – tomatoes, potatoes, cabbage, broccoli, fruit trees.
Asparagus – tomatoes, parsley, basil.
Aubergine – broad beans, marigold, peppers, mints, tarragon.
Beans – spinach, radishes, dill, celery, carrots, broccoli, peas, potatoes, cabbage, rosemary, cucumbers, bay leaves, sage, aubergines and strawberries.
Broccoli - alliums, nasturtium, rosemary, dill, chervil, rhubarb, sage.
Cabbages – celery, beetroot, alliums, dill, potatoes, rosemary, onions, chamomile, hyssop, thyme, sage, chamomile, rhubarb.
Carrots – peas, rosemary, onions, chives, lettuce, sage, beans, tomatoes, leeks, radishes.
Celery – onions, broad beans, nasturtiums, cosmos, snapdragons, tomatoes, garlic, leeks, dill, cabbage, cauliflowers.
Courgette – nasturtium.
Cucumber - sunflowers, peas, radishes, carrots, dill, beets, nasturtiums, chamomile, garlic.
Chives – sunflowers, tomatoes.
Coriander – plant with anything troubled by aphids.
Garlic – plant with anything troubled by aphids, especially roses and raspberries. Also cucumbers, peas, lettuce, rhubarb and celery.
Leeks – apple trees, celery, garlic, onions, carrots.
Lettuce – dill, radish, carrots, beans, cucumber, strawberries, mints, chervil.
Mustard – cabbage, cauliflower, radish, brussels sprouts, turnips, kohlrabi.
Onion – kale, broccoli, tomato, carrot, lettuce, cabbage, chamomile, rhubarb.
Parsnips - peas, potatoes, beans, garlic, radishes.
Peas - carrots, radish, turnip, cucumber, beans, spinach.
Potatoes - horseradish, cabbage, beans, maize, carrot, celery, dead nettle, peas, petunia, onion.
Pumpkin – beans, catmint, radishes, tansy, marigold, nasturtium.
Radish - nasturtium, lettuce, pea, cucumber, chervil.
Rhubarb – cabbage, borccoli, beans, columbine, garlic, onions,
Strawberry – lettuce, broad beans, onion, spinach, caraway, borage, thyme.
Tomatoes – nasturtiums, marigolds, basil, onions, roses, asparagus, peppers, oregano, parsley, carrots, petunias, carrot, cucumber, mint, borage, alliums, pelargoniums.

Nasturtiums make a great companion plant. Image courtesy of Penny.

Personality Clash
Some plants really don’t get on. If your veg aren’t growing as well as they could do, it might be because they’re planted next to plant which is giving them grief. Watch out for these bad pairings:
Alliums - beans, peas, parsley.
Asparagus – onions, garlic, potatoes.
Aubergines – runner beans.
Beans – tomatoes, sunflowers, beets, kales, cabbage, alliums, chives, fennel, garlic.
Broccoli – mustards, tomatoes, peppers.
Cabbage – mustards, peppers, tomatoes, beans, strawberries, peppers, dill.
Carrots - dill, parsnip, radish.
Celery – asters, dill.
Cucumber - tomato, sage, potato, aromatic herbs.
Fennel - doesn’t get on with many plants.
Leek - beans, peas.
Lettuce – celery, cabbage, cress, parsley.
Nasturtium – radish, cauliflower.
Onion - beans, peas, parsley, leeks.
Peas - onions, potatoes, garlic, shallots.
Potato – sunflower, tomatoes, pumpkin, squashes, tomatoes, cucumber.
Pumpkin – potato.
Strawberry – cabbage.
Tomato – potato, fennel family, peas, potatoes, cabbage, rosemary.