Learning which plants to grow together can greatly increase your success in the garden, whether you want to cut down on spraying or watering, attract bees or scare off the neighbour's cat.

Companion planting - the idea that certain plants can benefit others when planted next to, or close to one another - has been around for centuries and could be the making of your garden.

With our current fixation on all things organic and environment-friendly, companion planting is really growing in popularity. It's easy to do and it can help reduce the number of chemicals used in your garden.

Marigolds are a great example of a pest-deterring companion plant because they produce a strong smell which repels most insects. Their roots also contain a pesticidal chemical which kills nematodes (microscopic parasites living in the soil).

Marigolds should be planted everywhere. Plant them amongst tomatoes and roses to deter aphids, and with potatoes and other roots, crops to protect them from nematodes. They'll also keep white cabbage moths away from your brassicas. And, if you plant them around your deck and barbecue area, they'll deter flies and mosquitoes.

Companion planting is about more than just repelling pests. I recommend planting basil with tomatoes. The basil not only repels flying insects, but it can also help improve the growth and flavour of your tomatoes.

Companion planting can also be used to attract beneficial insects which are essential for cross-pollinating flowers and fruit trees.

Celery is the perfect companion for brassicas because they attract aphid-eating ladybugs. They also attract bees and butterflies, so they'll help your garden pollinate. Celery is easy to grow and they're adaptable.

Companion planting can also be used to conserve moisture in your vegetable garden. I suggest planting squash vines beneath your corn and beans.

They shade the ground and, in doing so, regulate the soil temperature and conserve soil moisture, sort of like a living mulch. They also have small, prickly spines along their stems which can help deter rats and rabbits.

For larger furry pests, I recommend planting rue, a small herb that you can plant around borders to keep cats and dogs off your garden beds.

Cats and dogs dislike the smell of rue, so it's great for discouraging them from digging and doing other things in your garden. However, it's not a good companion for cucumbers, cabbage or herbs.

When it comes to companion planting there is a lot to learn, but your first step should be to have a good look around your own garden to see what's working and what isn't. Chances are you're doing some of the right things already.

Treat yourself to a good book on the topic or spend some time on google. Your garden will reward you for your effort.

Cauliflower and broccoli
Enjoys oregano and peas as well as dill.

Cabbage
Enjoys fragrant herbs such a sage, rosemary, coriander. They also thrive next to peas, beetroot and potatoes. 

Leeks and Carrots
Plant your leeks and carrots together. Leeks create a confusion of smells that repels the onion fly as well as the carrot fly. Planting these two together helps break up the soil which leads to stronger carrot roots as well as larger leek stems.

Sage
If you're a household of carnivores then sage is a very handy herb to have in the garden. Its leaves compliment all sorts of meats including chicken, fish and pork. And its complementary powers don't just start in the kitchen. Sage is said to protect cabbage from cabbage-moth and carrots from carrot-fly. It's also said to enhance the growth of both carrots and cabbage, and also strawberries and tomatoes.

Nasturtiums
Nasturtiums aren't a favourite of all gardeners but they're a great natural repellent against several pesky pests and in particular - aphids. These plant lice will be all over your garden at the moment and especially like the shoots on new roses. So if you want to try a natural repellent, plant orange coloured nasturtium around your roses.

They're also said to repel woolly aphids which are fans of apple trees. And if you grow them in amongst your vege patch they may attract and distract insects which would normally first feast on your brassica plants like broccoli, cauliflower, cabbage and kale.