Plants may either encourage or inhibit the health and productivity of their neighbours, whether in the vegetable or the flower garden. It is of great benefit to know which plants are companions’ for each other when you are planning what to sow where.
Some plants’ root and leaf excretions seem able to repel harmful insects, other plants may enrich the soil, or control weeds, or provide shelter.
Here are various tips that I’ve come across, offered with thanks to our many gardening ancestors for passing on their observations:
Plant sweet peas among your runner beans in June, you’ll attract more bees to the beans and improve pollination.
Aromatic herbs provide the traditional border for the vegetable garden. Their scents deter many garden pests and they also stimulate growth in nearby vegetables. Only fennel and wormwood are exceptions.
Peas and beans tend to flourish when grown by carrots, cauliflower and beetroot, but growing them close to onions will be to their detriment. And don’t plant gladioli anywhere near them if you want a decent crop.
Broad beans will be free from caterpillars if there are gooseberry bushes nearby.
Cabbages love herbs. Chamomile, mint, sage, hyssop, thyme, dill and rosemary all repel the cabbage-white butterfly. Tomatoes also keep the cabbage-white away. But strawberries grown too close to cabbages will have an adverse effect.
Carrot crops grow well with any members of the allium family, such as chives, onions and leeks. The alliums promote growth and flavour and suppress the carrot fly. The carrot fly also hates aromatic herbs. Grow carrots and onions in alternate rows.
Potatoes should never be planted with onions. Grow them with sweetcorn or broad beans instead.
Tomatoes like to be grown near basil, balm and borage, and do especially well if there are a few stinging nettles nearby. Tomatoes also make friends with asparagus.
Sweetcorn and pumpkins can be grown in alternating rows; the corn provides shelter for the pumpkins.
Marigolds are wonderful. They improve just about everything. Plant them all over the vegetable garden and let them self-seed in subsequent years. Potatoes, tomatoes, sweet potatoes, sweetcorn, strawberries, runner beans and French beans all do well with marigolds close by. It seems that the root secretions from the flowers kill eelworms (nematodes). Marigolds also suppress weeds such as ground elder, bindweed and couch grass, and deter wireworms, millipedes, greenfly and a host of other nasties.
Nasturtiums grown under apple trees are thought to protect the trees from woolly aphis. They also appear to deter whitefly.
Grow garlic to keep pests away from fruit, especially raspberries and grapes. It also keeps black spot off the roses. In fact, the Dorset author Thomas Hardy recorded the custom of planting an onion beside a rose bush to make the roses smell sweeter’.
There are lots more tips to be found in gardening magazines and books. Look out for them and pop them into a notebook. You will be helping future generations of gardeners.
