Top Tips For Companion Planting

When it comes to companion planting, remember that just like people, veggies have their favourite friends too. So, if you’re looking to increase the yield of your plants, protect them from pests and diseases and have a happy garden, then keep this guide in mind.

Not sure what companion planting is? Companion planting is when two plants are planted close together in order for them to benefit from one another. This could be pest control, providing a habitat for helpful insects and to improve your garden's performance.

Why should I use companion planting?

The benefits of good companion planting are plentiful. Plant the right things together, such as stronger, bigger, more sturdy plants with those that are a little more delicate, so that the tougher ones protect the others from sun, wind and harsh conditions.

Many seeds will ward off harmful soil pests as they exude chemicals through their roots into the soil, or produce lots of nectar and pollen that beneficial insects will like. Placing plants that pests don’t like amongst those that they love is a great defence!

A diverse mix of plants, instead of mono-cropping, makes for a healthier garden. Placing a row of cabbages solo in long rows is an open invitation to aphids and beetles.

What to consider when companion planting

When looking at your planting scheme, bear in mind which nutrients each plant will need. Some need more nitrogen, so planting them with another variety that doesn’t need much nitrogen will be beneficial to both – eliminating competition between them. For instance, the long taproots of carrots will get their nutrients lower down in the soil, lifting them up to a higher level, which can then benefit those plants with more shallow root systems. Peas and beans will draw nitrogen in, a nutrient that is really important for plants, making it more available for other plants.

Many flowers can be really useful in the vegetable garden – for instance, sweet alyssum flowers attract hoverflies whose larva devour aphids. Flowers also draw bees to pollinate early blooming fruit trees.

Something to bear in mind is to group your companion plants by their water needs. Those that grow deep roots, such as asparagus and tomatoes are happy together, as less frequent, deep watering is what they both need. Others like Swiss Chard and many beans have fairly shallow root systems so they need more frequent watering which soaks the top 5-10cm of soil.

Companion planting can also help improve the flavour of some plants when grown together. However, there are certain plants when placed close to each other that will stunt each other’s growth. This will cause trouble in the garden. So try not to plant onions, fennel or garlic next to your beans or peas – rather plant the garlic underneath roses which will help repel aphids.

Which flowers can I use when companion planting?

The first thing many seasoned veggie gardeners will put into their patch are marigolds. These are your first line of defence against a multitude of pests. They have a scent that many bugs don’t like, and are particularly good at repelling nematodes that attack the roots of your veg. Calendula is also a natural repellent for many harmful nematodes, and will be really beneficial to your tomatoes and asparagus.

Another is nasturtium, which will attract aphids to them, keeping them off your prize veggies, and all you need to do is break off the heavily infested stems and leaves and drop them in the bin.

Rosemary and Artemisia afra  (African wormwood) are natural insect repellents. But if you’re wanting to attract the good bugs into your garden, then make sure you’re growing carrots, fennel and yarrow for wasps, ladybirds and hoverflies.

With summer months fast approaching, we’re all looking forward to growing tomatoes again. Probably one of the most popular crops to grow along with spinach and Swiss Chard. The way to protect your ‘love apples’ is to plant dill and basil alongside them, as they’ll not only be natural protectors against bugs like hornworm, but will also improve the tomatoes’ flavour.

A quick guide to companion planting

ASPARAGUS

Plant with: basil, coriander, marigolds, nasturtiums, oregano, peppers, sage, thyme, tomatoes

Keep away from: onion, garlic, potato

BASIL

Plant with: asparagus, oregano, tomatoes, peppers

Keep away from: sage

BEANS

Plant with:  marigolds, beetroot, cabbage, carrot, cauliflower, celery, cucumber, maize, potato, strawberries

Keep away from: dill, fennel, all members of the onion family

BEETROOT

Plant with: asparagus, onion, kohlrabi, bush beans, lettuce, cabbage family

Keep away from: mustard seeds, pole beans

BROAD BEANS

Plant with: broccoli, lettuce, carrot, celery, corn

Keep away from: fennel, onion

CABBAGE

Plant with:  beetroot, celery, chives, dill, onions, rosemary, sage, thyme

Keep away from: dill, fennel, all members of the onion family

CARROTS

Plant with:  basil, chives, lettuce, onions, peas

Keep away from : broccoli, cabbages, cauliflower, dill, fennel, potatoes

CAULIFLOWER

Plant with: beans, oregano, celery, hyssop

Keep away from: potatoes, tomatoes, peas, nasturtium

CLERY

Plant with:  marigolds, beans, broccoli, cabbages, leeks, parsley, spring onions, tomatoes

Keep away from: nothing really bothers celery, so plant at will!

CUCUMBER

Plant with:  beans, green peppers, lettuces, nasturtiums, radishes

Keep away from: herbs, melons, potatoes

EGGPLANT / AUBERGINE

Plant with:  basil, beans, lettuce, peas, potatoes, spinach

Keep away from: no need to keep away from anything else.

KALE

Plant with: cabbage, dill, potatoes, rosemary, sage

Keep away from : strawberries, tomatoes

LEEKS

Plant with: carrot, celery

Keep away from: legumes

LETTUCE

Plant with: beetroot, cabbages, carrots, radishes, strawberries

Keep away from: broccoli

ONIONS

Plant with: beetroot, cabbages, carrots, lettuces, peppers, spinach, strawberries, tomatoes

Keep away from: beans, peas, sage

PEAS

Plant with: carrots, potatoes, radishes, leafy greens, eggplant

Keep away from: garlic, onions

PEPPERS

Plant with: beetroot, carrots, celery, lettuces, maize, parsley, pumpkin, radishes

Keep away from: beans

POTATOES

Plant with: beans, broccoli, cabbage, eggplant, kale, marigolds, maize, onions, peas, strawberries

Keep away from: cucumber, melons, pumpkins, squash, sunflowers, tomatoes, turnips

PUMPKIN AND BUTTERNUT

Plant with:  beans, garlic chives, mielies, radishes

Keep away from: potatoes

RADISH

Plant with: beets, carrots, peas, spinach, beans

Keep away from: brassicas

SUNFLOWERS

Plant with: mealies

Keep away from:  beans, potatoes

SWISS CHARD

Plant with:  beetroot, beans, cabbages, celery, green peppers, onions, peas, strawberry

Keep away from: grapes, potatoes, sage

TOMATOES

Plant with : marigolds, basil, carrots, celery, chives, onions, parsley, sage, stinging nettles

Keep away from: kohlrabi, potato, fennel, cabbage, corn

ZUCCHINI / BABY MARROW

Plant with: nasturtium

Plant them everywhere!