Imagine a thriving garden, bursting with healthy produce, pest and disease free, without the aid of sprays, chemicals, and general human interference. That's the brilliant idea behind companion planting and crop rotation.
Companion planting is the planting of certain crops near or far away from each other with the goal of providing pest control, attracting beneficial bugs, providing nutrients for plants and more.
It can be done in edible gardens of any size, and something I really try to practice in my small plot. There are certain companion planting suggestions you may have heard before, such as planting peas or beans (which are nitrogen fixers) after nitrogen hungry brassicas. However, it goes so much further than that.
Many companion planting tips and tricks are passed down from gardeners of generations ago. Not all of them have a scientifically proven backing and are more based on years of gardening experience. That is why companion planting guides are exactly that, guides, and they can be extremely helpful but the ultimate goal as a gardener is to find what works for your own garden.
Crop rotation (not planting your plants in the same space year after year), helps keep up soil fertility and stops the build-up of soil-borne diseases. Using a companion planting guide and practicing crop rotation will encourage a healthier garden.
There are many ways to do crop rotation, I personally divide my crop rotation roughly into three key groups. My garden is small so crop rotation is not easy but I practice it the best that I can.
Group 1: Heavy feeders such as brassicas, celery, corn, eggplants, garlic, pumpkins, tomatoes, and potatoes.
Group 2: I follow group 1 by sowing legumes (beans, peas...etc) to return nitrogen to the soil
Group 3: After group 2, I sow light feeders such as carrots, beetroot, parsnips, turnips, and radish, then start again with Group 1.
I sometimes switch between planting group 2 or 3 after group 1, depending on the season. The main point is that I try not plant from the same group two times in a row.
As I have a very small space, most of my vegetables are squeezed in very close together. This is when companion planting is important as certain things can inhibit the growth of others.
If you've never looked into companion planting before, today I'll run through A to Z of some of the things we can find in our home gardens and how companion planting can help.
We can only grow basil for a shorter period of time in New Zealand, so when the hotter months come along I cram it where I can. When it flowers bees love it and its strong scent repels whiteflies and houseflies. Basil grows happily alongside tomatoes, asparagus, and capsicums.
Borage is amazing anywhere in the garden. It is a ‘dynamic accumulator’. Borage roots pull up trace elements from deep within the soil. These elements release as the borage break down. Plants nearby with shallow roots can then take these up. It makes a brilliant compost addition too.
Brassicas (Broccoli, Brussel Sprouts, Cabbage, Cauliflower, Kale...)
Brassicas are happily planted alongside beans, beetroot, celery and onions but dislike tomatoes and can stunt the growth of strawberries. Don't plant your brassicas in the same space two years in a row as this can heighten the chance of clubroot disease.
Planting a herb border around your brassicas of borage, sage, rosemary, hyssop, dill, and mint can help repel the white butterfly as well as attracting bees.
A must have in a permaculture garden. Comfrey is rich in nutrients like nitrogen, potassium and phosphate so makes an excellent liquid fertiliser for tomatoes or other fruit-bearing plants. Chopped comfrey makes a wonderful green mulch as all the nutrients in the leaves will return to the soil when they break down. Plant comfrey around fruit trees to provide a self-mulching service. As the leaves drop they'll feed the trees.
Corn grows well with pumpkins as pumpkins provide a ground cover that helps conserve water in the soil. They grow well with cucurbits such as melons and cucumbers as well as beans and sunflowers.
Cucumbers aren't fussy but they do very well when planted by beans, sunflowers, and corn as the height of these plants can provide some shade for the cucumbers.
They do well planted next to bush beans as they'll absorb the extra nitrogen these give off. They don't do well when planted next to something too tall that will shade the sun.
Fennel is said to inhibit the growth of most other vegetables. I have tested this theory many times though and have found no problems with planting fennel around other veggies.
Leeks in rows, alternated with carrots can help repel carrot fly. Leeks grow well with celery too, in rich compost. Keep leeks away from any legumes.
Legumes (Peas, Beans, Chickpeas, Lupins...)
Legumes are wonderful in the garden. They take gaseous nitrogen from the air and store it in their roots. Their roots have little nodules that contain a bacteria that converts this into a form that other plants can absorb. When the plants are finished and breaking down in the soil, they return the converted nitrogen back to the soil for other plants to take up.
Legumes grow happily alongside beetroot, brassicas, carrots, celery, cucumber, corn, lettuce and potatoes.
They don't grow well near alliums (garlic, onions, etc) as alliums let out a compound that can inhibit legume growth.
Lettuce does well when planted alongside beetroot, carrots, radish, onions, and strawberries. Alternating lettuce with some french marigolds can help repel insects.
Nasturtiums are great when left to wander around your garden. They help repel white fly and keep other bugs off your vegetables by acting like a ‘trap crop’, sacrificing itself to save your produce. Planting alongside radish can give your radishes a more peppery taste.
Onions need to be kept clear from any legumes but do well planted alongside beetroot, carrots, and lettuce.
Parsnips do well when planted with beans, peas, and potatoes but avoid planting with carrots and celery as they may compete for nutrients.
Phacelia (purple tansy)
Purple tansies are fantastic insect repellants in the garden and can be planted virtually anywhere. They work great as trap crop, especially for green vegetable stink bugs!
Potatoes do well when planted alongside legumes, corn, onions but keep them away from tomatoes, cucumbers, melons, and pumpkins as these can make your potatoes susceptible to blight.
Pumpkins do well alongside corn as they provide a ground cover which keeps the the soil cool in the hot summer and helps conserve moisture. Keep pumpkins away from potatoes.
Silverbeet does well when planted alongside lettuce, onions, and beetroot.
Strawberries dislike all brassicas but do well when planted alongside borage, lettuce, and spinach.
Tomatoes grow well planted near asparagus, basil, celery, and carrots. Keep them away from brassicas, potatoes, and fennel.
Planting basil and marigolds around your tomatoes can deter pests.
Growing zucchini alongside nasturtiums will help protect them from insect attacks. They also grow well alongside corn and beans but keep them away from potatoes and pumpkins as they will compete for nutrients.
What are your favourite companion planting tips?