Companion planting is a fantastic tool that all gardeners should take advantage of.
It is an organic, chemical-free way of designing and planting your garden. It reaps the benefits’ nature can bring. The mixed cropping of different plants offers a wealth of opportunities to discover.
The main aim of companion planting is to deter pests and attract beneficial insects. Also, it can boost harvests and improve the flavor of crops.
I would recommend reading our previous companion-planting piece, where I looked at the background and advantages of companion planting.
Below, I look at 12 of the best vegetable companion planting alliances. Ones that growers should consider for their patch.
But, where there are good combinations, there are also bad. I also cover some combinations of vegetables to avoid that should not be grown together.
What type of vegetables grow better next to each other?
Sweetcorn, Beans, and Squash
One of the most famous companion planting combinations is known as the Three Sisters.
It is a traditional method of multi-cropping a bed with sweetcorn, beans, and squash plants.
Know that all three (mentioned above) of the companion plants offer benefits to the other. It is a fantastic example of crops all helping each other out.
The large leaves of the squash protect the roots of the sweetcorn from excess sunlight. They also act as a weed suppressant and help prevent water evaporation from the soil.
The tall, upright growth habit of the sweetcorn also allows the beans to climb up.
Finally, the beans are nitrogen fixers and put nitrogen into the soil. This is taken up by both the beans and the sweetcorn.
Pepper and Basil
These two are a wonderful companion plants. Friends: Basil is an excellent companion to pepper plants and can help repel aphid, spider mite, mosquito and fungus. Basil is said to improve the flavor of peppers, too.
Other great companion planting include onion, spinach or tomato.
Tomatoes and Basil
Another classic companion planting combination is to grow tomatoes and basil plants together.
Both crops thrive in the same warm conditions. Also, the herb increases the flavor and yield of the tomato plants.
Basil even repels pests that attack tomatoes. This includes aphids, mites, flies, asparagus beetle, and tomato horn worms.
Potatoes and Cabbage
These two crops are staples of classic roast dinners. They form a good partnership as companion plants, as well as going together well on a plate.
The growing style of each suit them being together. Cabbages have shallow root systems. This ensures the crop does not compete for nutrients with the deep roots put out by potatoes.
Cabbage also helps potatoes grow better and improves the flavor of the tubers. This includes all plants in the cabbage family, including broccoli, cauliflower, and kale. Other options that do the same include sweetcorn and beans.
Lettuce and Garlic
There are several options for lettuce companion plants. But the combination of lettuce and garlic offers two benefits to the grower.
Firstly, garlic can protect lettuce leaves from being ravaged by a wide range of pests.
Garlic is a great companion plant for many crops, as many pests are repelled by the strong smell. It is thought most small and flying pests can be repelled by garlic. This includes the likes of aphids, flies, mites, and slugs.
Secondly, growing low-lying lettuce alongside garlic bulbs forms a ground cover. This stops weeds from populating the area and competing with garlic for nutrients.
Carrots and Salad Onions
Carrot fly wreaks havoc on carrots, as well parsnip, celery and celeriac, and the larvae feed on the roots.
The pests sense the carrots by the smell emitted from the root crops. They can detect that smell from miles away.
Picking carrot companion plants that confuse enemies with distinct smells is one solution.
Intercropping with salad onions will mask the smell given off by the carrots. It will confuse the pests. Alternative allium like garlic, leeks, or shallots will also work.
Cucumber and Radish
Radish is a really simple and fast-growing crop. Their speed of growth means they are ideal to grow alongside slower-growing crops. This is a great way of efficiently using space.
Cucumbers are one crop that has a long growing season and works as a great radish companion plant. There are multiple benefits in the relationship between the two crops.
They both need lots of sunshine and thrive in similar conditions. Radishes do also help repel cucumber beetle. Cucumber is also regarded to improve the growth of radishes.
Broccoli and Onions
Brassicas like broccoli are susceptible to being attacked by many pests. Common culprits are aphids and cabbage white butterflies.
Planting onions next to broccoli helps repel pests by masking the scent of the brassica. It is the sulfur in onions that creates the odor which repels a wide range of pests.
Gardeners claim onions improve the flavor of broccoli when grown near each other. The growth and flavor of broccoli are also reputed to be improved by nearby celery or potatoes.
The growing style of the plants also benefits each other. The narrow, upright onion foliage fits well between the spreading growth of brassicas.
Aubergine/eggplant and Peas
Aubergines are hungry plants. They require lots of added fertilizer or nutrients to grow big and strong.
Growing peas, or another legume, nearby can help. It is an organic way of helping those hungry plants get the nutrients they need to grow big and strong.
Legumes such as peas, pole beans, or bush beans fix nitrogen in their roots and add nitrogen back into the soil. This makes the soil more fertile and gives a good boost to the aubergine.
Beetroot and Cauliflower
Plants in the cabbage family are great partners in the garden for beetroot.
The beets actually add essential minerals and nutrients to the soil as they grow. Beetroots draw water and nutrients from deep in the subsoil with their long roots.
This enriches the quality of the soil near the surface and offers a boost to the crops growing around it.
In particular, it helps nearby cauliflowers grow big and strong. Other crops that can work include cabbages, brussels sprouts, or kale.
Radish and Carrots
The speed at which radish grows is beneficial to carrots. The radishes grow quickly and loosen the soil as they sprout and grow.
By the time the carrot seeds germinate, the radishes should have done the work of loosening the soil. This helps the carrots to grow straight and strong.
The quick-growing radishes can also form a canopy over the young carrot seedlings. This helps keep moisture in the soil.
And when they are harvested, the carrots can prosper in the soil left by the radishes.
What vegetables can not be planted next to each other? And Why?
There are many positive relationships that can be achieved by companion planting. But, there are some vegetables that do not work as a companion plant to another.
Take care to avoid some of the combinations that do not like growing together.
Avoid Smothering Crops
Make sure not to grow plants that sprawl, such as squashes, alongside smaller plants. The smaller crops, like leafy greens, can be asphyxiated by the fast, sprawling growth of the squash or pumpkin. Very important.
Don’t Block Sunlight
Some plants grow very tall. They can prevent other smaller plants from accessing the sunlight they need to grow.
For example, be wary to not plant tomatoes, which love sunlight and lots of it, right next to climbing beans. The tall beans can cause the tomatoes to live in the shade.
Any usage of very tall-growing plants should be done with the consideration of others in the vicinity.
Perils of Mixing Heavy Feeders
Don’t plant two crops that are heavy feeders next to each other. It means they must compete for vital nutrients in the soil.
The likes of tomatoes or corn should not be planted next to each other. They both need lots of nutrients.
Also, courgettes/zucchini will struggle next to potatoes. They cannot compete with the latter for nutrients.
While some combinations improve growth and flavor, some can inhibit it.
An example of this is to not plant cucumbers near some strong aromatic herbs. They can impair the flavor of the cucumbers. Sage is even thought to actually stunt the plant’s growth and flavor.
Best helpers insects helpers
- Dill – charms ladybugs and in return they will chase up the white flies, aphids, tomato horn-worms, spider mites, cabbage loopers, and other. Note that dill can grow wild in wet regions, whether in dry climates, dill is the opposite.
- Marigolds – stops mosquitos, caterpillars and aphids alike and makes a perfect partnership with bees by preying on aphids. Do plant them very close to tomatoes and peppers!
- Mint – attracts damsel bugs which kill the potato beetles, caterpillars, cabbage worms, etc. To protect the Mint plants, share them with the likes of fennel in small containers.
- Coriander (Aka cilantro) – green lacewings love it, and in return they feed on whiteflies, aphids, and mealybugs.
To Sum Up Do Your Research
Vegetable plants all have their friends and enemies. There are lots of great combinations to take advantage of. But use caution not to put vegetables together that will have a negative effect on each other.
Follow the steps above.
Research what works well as companion plants when planning a vegetable garden.
See here for a more complete guide to companion planting combinations. It lists allies and enemies for a wide range of vegetables. These are compiled by university agriculture experts.
Happy planting and share your experience with us in the comment box below.