Whether you are planting a new garden or replanting one that has been growing for years, attention to companion planting is guaranteed to improve your homegrown crops.

It’s a simple concept based on the way nature works… naturally. For instance one plant’s enemy is another plant’s food. Some bad bugs have pet hates, so by planting or introducing what they don’t like, you can protect the plants that they would otherwise feed on. And then there are plants that have something to offer other plants, be it shade, or some sort of nutrient they put into the soil. You will also find that some plants provide other plants with specific nourishment.

A Fatal Attraction for Bad Bugs

Here the trick is to plant whatever attracts the nasties. For instance, the tiny black aphids that chomp their way through young cabbages, broccoli and other veggies provide a feast for nasturtiums. These easy-growing herbs attract the aphids with their sticky juices that effectively end up smothering large numbers of these damaging mini-bugs.

Growing Plants that Deter Bugs

An interesting fact about companion planting is that not all plants like – or dislike – the same bugs. Similarly, while some plants (like carrots) love tomatoes, some plants (like dill and asparagus) loath tomatoes.

Some examples of plants that will deter bad bugs include:

• pennyroyal that keeps worms and beetles away from strawberries,
• asparagus and marigolds both help to protect tomatoes from harmful nematodes in the soil,
• lemon verbena that will keep flies, aphids and midges away from all vegetables and fruit trees,
• just about any plant that is related to garlic or onions, including chives (in particular garlic will chase off potato bugs).

Plants that Have Other Benefits for Companion Plants

Providing shade is a biggie, but you need to be sure that the shade giver actually likes the plant you choose to be its companion. Sweetcorn is an excellent provider of shade and works well with a lot of other plants, including pumpkin that will creep around towering corn plants, producing fruit at ground level. It can also be a support for some climbing flower plants.

Fennel is one of the few plants that most other plants hate! But there are a couple of veggies that like fennel, including gem squash and spring onions (or green onions).

There are many more plants that benefit from just about anything. Yarrow is a good example as it attracts ladybirds and wasps that both love to eat aphids. Most plants are fond of yarrow.

Picking Plants that Deter Bugs

Just as we can use leaves and other parts of certain plants to make organic pesticides, or to rid our environment of pests (scented geraniums are great for mosquitoes, freshly crushed tomato and basil leaves will usually get rid of flies, and sprigs of catnip will get rid of ants), there are similar steps we can take within the garden itself. Here are two possibilities:

1. Don’t rake up the leaves from oak trees. Instead use them to create a barrier around garden beds where lettuces are growing and they’ll keep the snails and slugs away.
2. If you’re a fan of grapefruit, cut them in half and scoop out the fruit, then use the skin “shells” to attract slugs. Simply place them upside down in any part of the garden where slugs are a problem and remove them, together with slug invaders, the next day.

Ultimately you need to be aware of which plants do well together, and which don’t. Probably one of the very best examples of companion planting is illustrated by the relationship between tomatoes and asparagus. They really are best friends because not only will the solanine contained in tomatoes protect asparagus plants from insect attack, but it also encourages growth in the asparagus.

Annette Welsford is the author of best selling book Companion Planting for Veggies