Companion Planting for Vegetable Gardens

4 November 2010, written by Kate Bradbury

There are plenty of ways in which you can work with nature to help cultivate your crops successfully. For example, you can plant basil next to tomatoes to help ward off whitefly or you can use nasturtiums to lure aphids away from your pole beans. Clever planting schemes can deter pests or lure beneficial insects such as ladybugs and lacewings on to your plot. Some plants can even be used as structural support for others.

Deterring pests

Simply by planting a row of strong-smelling plants next to a row of vulnerable vegetables, you can ward off many pests (such as carrot root fly, white fly and aphids). Carrot root fly can smell carrots from up to a mile away. But If you plant alliums (such as leeks, onions or garlic) near your carrots, this masks their sweet, carroty smell. Alliums also deter slugs. So try growing salad leaf crops (such as lettuce and rocket) amongst them. Further, alliums prevent fungal infections. So a row of onions planted near strawberries helps to prevent the strawberries from developing mold.

Basil and marigolds act as a natural insect repellent when planted amongst tomatoes, helping to ward off whitefly. Similarly, a row of nasturtiums planted amongst beans attracts aphids away from your crop. This is because nasturtiums are more appealing to aphids than beans, so the pests will always go for their favored treat if there’s the option to do so.

The following plants help deter pests from your crop:

Basil – wards off whitefly when planted amongst tomatoes
Nasturtium – attracts aphids away from beans
Alliums – confuse carrot root fly and protect against slug damage
Lavender – confuses pests
Nettles – attract cabbage white butterflies, keeping them away from brassica crops

Beneficial insects

Planting brightly colored flowers near your crops will attract a wide range of insects to the area. More bees visiting your plot will result in more pollination of your vegetable blooms and therefore lead to bigger yields. Attracting ladybugs and lacewings to your crop will also help reduce damage from aphids. The predators will lay their eggs on your crops. These will hatch into larvae which can each eat up to 150 aphids per day.

The following flowers and herbs are ideal for attracting beneficial insects to your crop:

Candytuft
Cilantro
Sunflower
Lavender
Echinacea

Please see our full article on Flowers for Vegetable Gardens for a detailed illustrated guide.

Support network

Using certain crops to help others is another great way to ensure success in your vegetable garden. The traditional ‘three sisters’ approach involves planting a bed with sweetc orn, beans and squash plants (such as pumpkin and zucchini) all growing together. Each plant provides natural shelter and protection for the other. The large leaves of the squash plants shade the sweet corn’s roots from sunlight. They also act as a natural mulch by suppressing weeds and preventing moisture from evaporating from the soil’s surface. The tall stems of the sweet corn provide a sturdy support for the beans to climb up. In turn, the beans fix nitrogen into the soil, which benefits both the sweet corn and the squash plants.

Other sturdy plants (such as Jerusalem artichokes) can provide shelter from wind for vulnerable crops. You could also try growing spinach between broad bean plants (the fava beans will offer protection from slugs and wind damage) or grow cabbage seedlings amongst leeks to hide them from pigeons.

Summary

Use strong-smelling vegetables such as alliums (onions and garlic) and herbs (rosemary and basil) to confuse pests and prevent them from attacking your crop
Attract beneficial insects to your vegetable plot by planting flowers and herbs (such as candytuft and cilantro)
Build a support network - use larger vegetables to protect smaller plants and seedlings by acting as a wind block or as a climbing support