Some of our readers have been asking for vegetable companion plants. So, we did some research to find more. Here’s what we found.
The most popular companion plant vegetables are corn, beans, and squash (the Three Sisters). Corn provides a trellis for the beans, the beans supply nitrogen, and the squash provides a ground cover. However, many vegetables can be paired such as carrots with onions, broccoli with lettuce, and potatoes with corn.
So, while these are the best companion vegetables, what benefits do they each bring to the garden, and what are their other friends and foes? Let’s take a closer look.
Companion plants for potatoes include corn, onions, garlic, thyme, clover, and brassicas. Avoid planting potatoes near carrots, cucumber, squash, tomatoes, raspberries, and sunflowers.
Potatoes are a staple in most gardens, especially for survival and self-sufficiency gardens. This is because potatoes are easy to grow and are high in calories. They can also grow in many zones as an annual, usually 3-10 (source).
However, potatoes are susceptible to many pests and diseases. The good news is that potatoes have quite a few companion plants that boost their resistance (listed above).
The most common pest potatoes are plagued by are nematodes. Nematodes are roundworms in the soil which attack the roots of many plants, including tomato, pepper, eggplant, okra, cucumber, squash, and of course—potatoes. These nematodes often afflict home gardens and have no available chemical pesticide.
Luckily, marigolds, are natural repellents towards nematodes because they produce a substance called alpha-terthienyl, which is deadly for the nematodes.
Potatoes are also commonly affected by Colorado potato beetles, which peas were found to repel (source).
For best results, plant carrots with onions, tomatoes, lettuce, legumes, and leeks. Avoid planting carrots near radish, parsnip, and dill.
Carrots are biennial root vegetables commonly grown as annuals, and also grow in zones 3-10. They help other plants by breaking up compact soils and repelling some pests such as onion flies.
Keep in mind that carrots need rich, loose, and well-draining soil. It’s fairly common for carrot growers to accidentally get baby carrots because the ground is too hard or compact for the root to grow.
However, the ground will loosen naturally over time as the roots of plants penetrate it. Their roots also hold groundwater.
Pro-tip: You can cut off the carrot tops and replant them. They’ll quickly regrow new carrot roots!
Cabbage plants are part of the brassica, or mustard family, which includes broccoli, cauliflower, kale, collards, swede, radish, turnip, and Brussels sprouts. As a result, you can often interplant brassicas with each other.
Cabbages also like being planted next to legumes, clover, celery, and onions.
However, as with many other vegetables, cabbage plants are highly susceptible to snails and slugs. For this reason, plant snail and slug repellent companion plants near cabbages, such as sage, rosemary, and lavender (source).
Avoid planting cabbages near grape and strawberry plants.
Pro-tip: Avoid the common issue of cabbage heads splitting by watering lightly and gradually after a drought. This avoids the thirsty cabbage from drinking water too quickly, which causes the head to swell and crack.
Cabbages can grow in most zones (typically zones 1-10), depending on the variety (source).
Kale has recently become popular again due to its ease of growth and nutrition. It’s a descendent of wild cabbage, which is native to parts of Europe and Asia and has been grown as a food crop for over 4,000 years (source). Kale grows best in USDA zones 7-10 and prefers full sun and well-draining soil.
Ideally, plant kale with other brassicas and alongside legumes, celery, and onions.
Avoid planting kale near pepper plants. Some say that kale also has a hard time growing near tomato plants.
Another brassica, broccoli is a perennial native to the Mediterranean and parts of Asia (source) that can be grown in zones 2-11. While broccoli has a large range of growing zones, they are typically grown as an annual. They also require full sun, and rich, well-draining soil.
Broccoli is best planted with companion plants such as legumes, celery, onions, and especially—lettuce. In fact, interplanting broccoli and lettuce have been shown to improve both of the plant’s yields (source).
Avoid planting broccoli with asparagus, peppers, and strawberries.
Pro-tip: The most often consumed part of broccoli is the head, but the broccoli stalk and leaves are also edible, tasty, and nutritious.
Lettuce is also native to the Mediterranean and is hardy, growing in zones 2-11. As mentioned above, interplanting lettuce with broccoli improves both plants’ yields.
You can also grow lettuce with legumes, onions, beets, radish, and carrots. Avoid planting lettuce with parsley, celery, and cabbage.
Lettuce can also commonly get pests including aphids, which suck the sap from the leaves, quickly destroying the plant.
Pest-repelling companion plants include aromatic plants such as garlic, chives, sage, rosemary, and lavender.
To combat aphids, you can plant companion flowers nearby such as nasturtiums, sunflowers, dill, calendula, and cosmos.
For more pest-repelling companion plants, visit my other post: 7 Companion Plants That Repel Pests
Naturally, the best companion plants for corn are the other two sisters, beans and squash, but some lesser-known sisters such as amaranth are also good choices. Avoid planting celery and tomatoes near corn.
Corn, while technically a grain, is a popular companion plant. This is partly due to it being one of the three sisters, as well as its superb talent of being a living trellis for other plants.
Tomatoes, in particular, share a common pest with corn—the tomato fruitworm is identical to the corn earworm (source).
8. Sweet Potatoes
Sweet potatoes are one of my favorite vegetables to grow as both their tubers as well as their leaves are edible (unlike regular potatoes). While sharing a similar name, regular potatoes are part of the nightshade family and not related to sweet potatoes.
Plant sweet potatoes alongside okra, spinach, and garlic, but avoid placing near squash and passion fruit (source).
Sweet potatoes make one of the best ground covers as even a small shoot can grow a whole other plant, creating its own separate tubers. These plants naturally vine out and cover a large area, providing the soil with shade and heavily reducing evaporation.
Pro-tip: Harvest sweet potatoes in the fall and early winter, when the leaves start to die from the cold weather. Use a pitchfork to loosen the soil and remove the tubers.
Spinach grows best with companions such as brassicas, legumes, and strawberries.
Compared to brassicas, spinach doesn’t take much garden space, so they can be interplanted wherever you have extra space. Generally, allow spinach at least 3-4 inches of space from other plants.
Spinach is extremely hardy in the garden, surviving down to 15ºF (even colder if it has some shelter). Because of this, spinach is an easy vegetable to grow in most hardiness zones, even in the winter months.
And if your temperatures commonly drop below 15ºF, you can still grow spinach. While large, proper greenhouses will work, even something as small as cutting the base off of a gallon jug of water and using the top will keep your spinach growing in the cold.
So, not only are you repurposing plastic, but you’re providing your spinach plant with a mini greenhouse! In fact, spinach seedlings that are started indoors are known to be difficult to transplant (source), so planting in the garden with some shelter instead is typically a more effective growing method.
Companion plant onions alongside legumes, beets, carrots, cucumbers, strawberries, and brassicas. Onions are also good at repelling pests, such as carrot flies. Avoid onions with asparagus and legumes.
Onions will grow in just about any growing zone, but do best in zones 5-6 (source). It takes about 100-175 days to grow onions, which is longer than most annual vegetables, so plan accordingly!
When planting, space the onions 6-8 inches from other plants to allow sufficient space for the bulb to grow. More compact planting can allow for 4-5 inches for each onion plant. Onions will still grow with fewer than 4 inches of space, but will mainly grow for their greens (green onions).
Pro-tip: If you ever want to appear like you’re a better cook than you are, throw some onions and garlic on the stove! Onions and garlic are some of the most aromatic ingredients and will get anyone excited for your cooking.
Need More Help?
You can always ask us here at Couch to Homestead, but you should know the other resources available to you! Here are the resources we recommend.
- Local Cooperative Extension Services: While we do our best with these articles, sometimes knowledge from a local expert is needed! The USDA partnered with Universities to create these free agriculture extension services. Check out this list to see your local services.
- Permaculture Consultation: Need help with a bigger project? Send us a message.
Want more info about companion planting with vegetables? Check out this cool video by GrowVeg.