COMPANION planting is the art of masking the aroma given off by certain plants with those of others, writes TOM ATTWOOD. It’s a technique most commonly used in vegetable gardening where you’ll use every tool in your armoury to protect that cherished crop you’ve been nurturing. A practical example of this technique is the companion planting used when growing carrots. If you’re lucky and do nothing you may escape the worst damage but it’s inevitable that carrot fly (Psila rosae) would eventually become a problem. The damage is caused by the larvae (or maggots) who will attack the rootlets of young plants. The solution? Growing onions, leeks and herbs such as Rosemary, wormwood, and sage nearby will act as effective repellents to the carrot fly and from my own experience growing chives next to a carrot crop worked exceedingly well. The most pungent leaves and stems such as those of the onion family that smell strongly to us will be even more impacting on insects and thus you have a safe, chemical free method of controlling what can otherwise be a recurring obstacle to healthy growth. Combining this principle alongside that of rotating where you grow your crops every season is highly effective and good all-round husbandry. It’s not only outside where companion planting is effective. If you have a greenhouse where you regularly grow tomatoes then it would be worth considering growing some basil alongside them. The basil helps the tomatoes to overcome both insects and disease, also improving growth and flavour. Plus you end up with two crops that make a superb salad when combined with a simple dressing of olive oil (as a side line, basil repels mosquitoes and flies, and when laid over tomatoes in a serving bowl will deter fruit flies). You will have to do some homework as the effects of certain plants can vary on the crop they are next to. Dill for example, works well alongside cabbages but will inhibit the growth of carrots. Arm yourself with a good book on the subject and you’ll never look back.

Next week: plug plants or seeds? Why you should consider both