by Saffyre Falkenberg
Bringing a wide variety of plants into your vegetable garden can have many benefits. Planting certain vegetables next to each other can encourage both plants to thrive. This unique process is known as companion planting.
Companion plants have many potential benefits for their partner plant counterparts. They can help each other grow by attracting pollinators or repelling pests in addition to providing beneficial nutrients, shade, or support. When you’re planning this year’s garden, make sure to check if the vegetables you want to grow have companions that will help your garden thrive.
Beets and Garlic
Planting beets and garlic together has many benefits. Pests such as root maggots, Japanese beetles, snails, and coddling moths that affect beets are repelled by the smell of garlic. Planting garlic near beets also improves the flavor of the beets, and the sulfur that garlic produces as it grows acts as an antifungal that helps prevent disease in the beets.
Beets grow best in deep, well-drained soil. Clay soils will be too heavy for beets to grow properly. Beets like cool weather, but make sure not to plant them until the soil temperature is at least 40 degrees Fahrenheit. Plant the seeds one to two inches apart in rows, and make sure to give the beets around one inch of water a week.
You should plant garlic in fertile, well-drained soil, spacing the cloves four to six inches apart. Position cloves with the pointy end pointing up, and push each clove one to two inches down into the ground. Make sure to water the garlic plants every three to five days when they begin to form bulbs.
Broccoli and Onions
By planting broccoli and onions in close proximity to each other in the garden, you can improve the flavor of your broccoli.
Broccoli is one of the most nutritious of all the vegetables out there, and it grows best in cooler seasons. It will fully mature within six to eight weeks. The plant does best in full sun but will also grow well in partial shade. Broccoli needs moist, fertile, slightly acidic soil. Plant seeds half an inch deep, or put transplants slightly deeper in the soil than they were before. Space plants 12 to 24 inches apart with 36 inches between rows. Water regularly, and try not to get the growing heads wet.
Onions are a bulbous, cool weather plant. You can either purchase onion bulbs that are ready to plant directly into the ground at nurseries or online. If you choose to grow onions from seeds, it will take up to four months for the plant to mature. The onion tops will grow in cool weather and form bulbs when the weather gets warm. Water about one inch per week, and make sure to keep the onions well-weeded, as the plants cannot easily compete with weeds.
Carrots and Leeks
Carrots are normally attacked by carrot flies, and leeks are affected by leek moths and onion flies. The carrots will deter the leeks’ pests, and the leeks will keep the carrots’ pests away. Basically, these plants are such good garden buddies because they act as repellents for each other’s pests.
To grow carrots, plant the seeds outside about three to five weeks before the last frost. Plant the seeds three or four inches apart in rows that are at least 12 inches apart. Try to grow them in full sunlight. The soil should be well drained and loose, and you should water the plants at least one inch per week,
The leek is a cousin of the onion that thrives in cool weather. Plant leeks in an area of the garden that gets full sun and that has fertile, well-drained soil. They need extremely fertile soil and lots of moisture in order to grow best. In order to get the kind of rich, white stem that is best for eating, the stem must be hidden from the sun in a process known as blanching.
Corn, Beans, and Squash
Growing corn, beans, and squash together is a method known as the three sisters, which was cultivated by indigenous Americans. The stalks of the corn support the beans, while the bean plant draws nitrogen from the soil, which helps the plants around it grow bigger and fuller. The squash has large leaves that grow close to the ground, acting as a weed deterrent for the corn and beans.
To plant sweet corn, make sure the soil is at least 65 degrees Fahrenheit before planting the seeds half an inch to one and a half inches deep. Plant the seeds 12 inches apart in rows, and make sure the rows are 30 to 36 inches apart. Plant your corn in an area that gets full sunshine and has well-drained soil. Water the corn deeply about once a week.
You can plant any variety of pole beans any time after the danger of frost has passed. They should be started from seeds, as attempting to transplant pole beans may actually kill the young plants. Sow the seeds about three inches apart. Normally pole beans require support, such as a trellis, but in this case, the beans will use the corn stalks to climb up. Water the plants regularly, especially during sunny days.
Traditionally, indigenous Americans used pumpkins in the Three Sisters method, but any winter squash will do. Pumpkins require a long growing season, typically beginning in late May or early June. You can plant the pumpkins in rows or in small mounds that help warm the soil and keep it drained. Plant the seeds one inch deep. The pumpkins should be planted in a spot that has both full sun and well-drained soil. They also need a lot of water, about one inch per week.
Cucumbers and Peas
Growing cucumbers and peas together will ultimately benefit the cucumber plant, as the peas will increase the nitrogen in the soil. The increased nitrogen will encourage the cucumber plant to grow bigger and heartier.
Cucumbers are a tropical vegetable. Cucumber plants need warm soil that has an acidic pH to grow. Plant the seedlings 36 to 60 inches apart, and use a trellis to support the vines as they grow. The trellis also conveniently keeps the fruit off the ground. Try to keep the soil damp with approximately one inch of water per week.
Peas are a legume that normally prefers colder weather, so in order to plant them with tropical cucumbers, you will have to support them with water and shade during summer months for a fall harvest. While any variety of pea will work for companion planting, snap peas grow on a trellis, so planting these will allow you to utilize the same trellis as the cucumbers. Peas need slightly acidic soil. Plant directly into the ground, as transplanting can damage the plants and affect the harvest later on. Try to water the peas daily once pods form to encourage higher quality.
Radishes and Spinach
If you plant radishes and spinach together, the radishes will help draw away leafminers from the spinach. These pests will not affect the root of the radish plant, which is the edible part.
Plant radishes about one month before the average date of the last frost of the season. Sow the seeds directly in to the soil, about half an inch to one inch deep and two inches apart in rows that are 12 inches apart. Radishes need a lot of sun and well-drained soil with a lot of moisture, but make sure the soil isn’t waterlogged.
You can plant spinach as soon as the ground thaws. Start the plant outdoors, as trying to transplant the spinach may damage the young plants. Make sure the spot you choose gets full sun to light shade and has well-drained soil. You can either sow the seeds half an inch to one inch deep or sprinkle the seeds over a large bed. Water regularly, and use mulch to retain moisture.
Tomatoes and Cabbage
Planting tomatoes and cabbage in the garden together will help keep your cabbages whole and healthy. Tomatoes repel diamondback moth larvae, which will eat large holes in cabbage leaves.
Plant tomatoes in late spring or early summer, as they thrive on warmth. Because of this, they also need full sun for about six to eight hours.
In order to keep the tomato plants off the ground, use a stake, trellis, or cage. Use approximately two to four inches of mulch to retain moisture and keep weeds from growing. The tomatoes will need a lot of moisture, so try to water them at least one inch a week, though you should water them more in the summer months.
You should plant fall cabbage about six to eight weeks before the first frost. Pick a spot that has full sun and well-drained soil. They are easy to transplant, so you can start them indoors if you want. When transplanting, make sure to plant them between one to two inches deep in rows between 12 and 24 inches apart. Cabbage needs an even amount of water, so make sure to water it about one to one and a half inches a week.
As you can see, there are many options for companion planting that can benefit your vegetable garden. If you’re considering any one of these options for this year’s garden, think about adding one of the companions to help your vegetables along. After all, there’s nothing wrong with more vegetables.
Common Questions and Answers About Companion Planting
by Erin Marissa Russell
How do you plant a companion garden?
You plant a companion garden by learning which plants make good growing partners for the plants you want to grow and making a plan for what you’ll grow together. Sometimes companion planting means having plants share the garden space at the same time, and sometimes it’s a more seasonal approach of turning the garden over to one plant as another’s season in the garden comes to an end. It’s important to do some research and planning before diving in, because some plant combinations just don’t work out and can actually be detrimental to each other’s growth.
How does companion planting work?
Companion planting is the practice of fostering beneficial relationships between plants that are grown together in the garden. A common example is the “three sisters” planting method of growing corn, beans, and squash together. In this arrangement, the corn offers a surface to support the beans as they grow vertically. The beans bring nitrogen to the soil, which is used by all three plants. The squash has large leaves that shade the ground like a layer of mulch would, protecting the soil and keeping it moist and cool while also discouraging the growth of weeds.
What should not be planted together?
For now, most of the information that’s out there about companion planting is anecdotal. Here, we’ve collected some of that information to make a list of the plants that should absolutely not be grown together in companion planting.
- Cucumbers and potatoes should not be planted together because they create pH levels that the other finds inhospitable. Cucumbers also don’t do well planted next to aromatic herbs.
- Keep members of the allium family (onions, garlic, leeks, and shallots) away from beans, beets, cabbage, carrots, corn, cucumbers, and strawberries. Onions are also a problem if they’re planted next to asparagus, beans, or peas, as they’re said to stunt their growth.
- Lettuce and cabbage should be kept away from one another. Cabbage is also a problem when it’s planted near tomatoes, pole beans, or strawberries.
- Don’t plant kohlrabi near carrots, eggplant, onions, parsley, peppers, or tomatoes.
- Corn and tomatoes both tend to fall prey to the same fungal infection, so they should be grown separately.
- Beans are rumored to dislike being planted near gladiolus flowers.
- Potatoes are susceptible to the same diseases as peppers and tomatoes, so keep potatoes growing far away from your pepper and tomato plants.
- Black walnut trees are detrimental to many other plants, but for vegetable gardening in particular, black walnut and butternut squash don’t make good partners for tomatoes or other nightshades, such as eggplants and peppers.
- Carrots and parsley should be planted far from one another, but when they have room to grow, they’ll attract beneficial insects to the garden.
- Don’t grow tomatoes with brassicas (including broccoli, Brussels sprouts, cabbage, collard greens, kale, kohlrabi, rutabagas, and turnips.) Tomatoes also make poor partners for potatoes and fennel.
Want to learn more about vegetables that grow well together and companion planting?
The Old Farmer’s Almanac covers Three Sister Planting Method
Cornell University covers Companion Planting
SFGate Homeguides covers Vegetables That Should Not be Planted Next Each Other
Nature’s Path covers How to Start Companion Planting
The Spruce covers Growing Garden Fresh Sweet Corn
The Old Farmer’s Almanac covers Growing Beans
The Old Farmer’s Almanac covers Growing Radishes
The Old Farmer’s Almanac covers Growing Pumpkins
The Old Farmer’s Almanac covers Growing Spinach
Bonnie Plants covers Growing Tomatoes
Bonnie Plants covers Growing Cabbage
Bonnie Plants covers Growing Cucumbers
Hobby Farms covers The 13 Best Companion Plants
Rodale’s Organic Life outlines 26 Plants You Should Always Grow Side By Side
Burpee explains All About Peas
The Old Farmer’s Almanac covers Growing Broccoli
Rodale’s Organic Life covers Onion Growing Guide
The Old Farmer’s Almanac covers Growing Carrots
Bonnie Plants explains Growing Leeks
The Spruce covers How to Grow Beets in the Home Garden
The Old Farmer’s Almanac covers Growing Garlic
Deep Green Permaculture outlines Companion Planting Table
Written by Saffyre Falkenberg
Author Saffyre Falkenberg began gardening with her grandmother as a child in Southern California. She continues to keep plants in her apartment in Texas and has a special love for succulents.