Many vegetable and herbs make good companion plants. They mutually support each other with nutrient sharing, filtering or protecting from heat or light, predator attraction, helping to resist bacterial infection, repel feeding insects, hiding from pests, and much more...
It is proven fact that planting mutually beneficial plants together will be effective against pests and will increase productivity. However, the reasons why are not always obvious - mostly it is just trial and error.
And you will have to do your own trial and error experiments to find the good companion plants for your garden as each garden is unique and each gardener has their own individual skills and experience. Plus each zone and region in the world has its own unique species of vegetables and their feeding pests.
However, some of the scientific facts are shown clearly in the results of the crop. For example: Tomato leaves produce a chemical which is toxic to some weevil species;
Tagetes (Marigolds) produce a chemical called Thiopene which repels soil nematodes;
An oil exuded from Turnip roots deters spider mites and pea aphids.
Mustard is also a useful option for nematodes.
Why not think outside the box a little with good companion plants such as growing herb paths.
These can be grown throughout the garden using Lawn Thyme or Chamomile.
The Thyme will mask the scent of the vegetables and attract beneficial predators while the Chamomile will enhance the stamina of the plants, help control bacterial invasions and of course help attract beneficial insects.
Grow Wattle trees around the garden as they fix nitrogen and the leaves can be used for mulch.
Wormwood repels mosquitoes. Tansy repels flies and ants. Basil works well for flies and mosquitoes. Fennel repels fleas. Rue deters cats.
Herbs do not like soil enriched with fertilizers or manures, but do like compost.
Most herbs prefer a well drained or sandy soil and may require more work in heavy soil.
Lupins and Sweet Peas are also nitrogen fixers and the flowers can be a lure for insects away from the veggies.
Growing some vine plants up trees and through large, stronger stalk plants will help camouflage them from insects and conserve ground space. You could also try growing pumpkins in the back lawn rather than the garden bed to conserve space.
Nasturtiums are a common plant for trapping aphids. They also deter whiteflies and squash bugs.
Basil and Tomatoes are a well known combination to control bugs like hornworms.
Stinging Nettle is a much overlooked garden helper. Most people just pull it out but it can be very useful as a companion plant. However, it can also be made into a tea to spray on ailing plants.
I have listed below the vegetables that grow happily in each other's company and the essential oil plant which works well interspersed in planting or used as a tea or spray in good companion plants.
Low growing fruits like strawberries and tall fruit trees also benefit from good companion plants.
Many gardeners grow their fruit trees in orchards of the same fruit, each tree planted at a distance from the next tree. This monoculture is unnatural and unproductive, and allows for the fruit to be easily accessible to birds and flying insects. Plant the trees closely together so their silhouette is camouflaged.
Interplant fruit trees with other fruiting trees whose fruit ripens at different times, or similar fruit trees which ripen in stages, either earlier or later or the pests will have a continual meal.
Grow deciduous trees with evergreens.
Grow vine fruit up the trunk and through the branches.
Confuse the feeding pests or hide the fruit from watchful eyes.
Grow smaller bushes under the trees to hide the fallen fruit which will attract birds because these birds will then start to work their way up the tree after consuming the fallen fruit.
Birds are territorial and are programmed to eat food growing in their own areas – usually native foods.
Over time they will adapt to introduced foods like the fruits grown commercially in orchards or the ones you have planted for home use.
To distract birds plant around the boundary of your garden native fruit trees which mature at the same time as your fruit trees and the birds will leave your fruit trees alone, mostly…
Inter-planting also protects against moisture loss, keeps the weeds down and shelters pest predators.
When planting vigorous companion plants under trees remember to slash or cut them back regularly.
Nasturtiums will protect against aphids, scab and molds on apple trees.
Legumes are a good general growth stimulant.
Southernwood repels moths.
Tansy repels flying insects.
All members of the onion family are good for inter-planting with fruit trees.
Nettles fix nitrogen in the soil and are a good plant under trees as they repel sap sucking insects, encourage earthworms and enrich the soil with calcium.
Wandering Jew is good under young trees but needs constant vigilance.
Dock is good under trees as it brings up deep nutrients to the surface.
Lantana surrounding a garden can be beneficial against sap suckers like aphids.
I have listed below the fruit trees which grow happily in each other's company and the essential oil plant which works well interspersed in planting or used as a tea or spray in good companion plants.
Keep an eye on your garden and remember some common sense realities:
A small companion plant will have minimal effect on its tall neighbour.
Always watch your plants to see what the effect is from its companion. Does the flowering actually help?
Do you have the pest in the first place?
Has the pest been eliminated or just moved next door to other plants?
Think about your garden and the layout you have or plan to build. Interplant flowers, herbs, vegetables, fruit trees, essential oil plants - making your vegetable garden as natural as possible and your bugs will be less and your plants healthier and heavier cropping.