Companion planting offers numerous benefits to the home gardener, whether practiced in the vegetable garden, herb garden, or even flower beds. If you are just getting started with this practice, the numerous possible plant combinations can seem impossibly overwhelming. This companion planting guide breaks down the basic details about companion planting and includes a list of individual companion plant guides so you can absorb the information one bite at a time.
What Is Companion Planting?
Companion planting involves growing multiple plant species together for cultural benefit. Sometimes this relationship goes only one way, and other times it is mutual. Although plants do, of course, compete with each other for resources, many have adapted to grow alongside and even work with other plants.
The science behind companion planting backs up the idea that a diverse garden is a healthy garden. And when you know which plants grow best together, you can maximize the benefits companion planting provides.
Benefits of companion planting
1. Maximized use of space
Plants have different spacing requirements and maturation rates, allowing you to pack more plants into less space. For example, you might plant a low-growing, fast-maturing vegetable under a taller, slower-growing plant and get two crops out of the same area from which you only would have gotten one.
2. Symbiotic nitrogen fixation
Some plants – namely legumes – fix nitrogen in the soil, while other plants require lots of nitrogen in order to grow. Many gardeners use legumes, like clover, as a cover crop, but you can also plant legumes and heavy nitrogen feeders right next to each other, like beans and potatoes.
3. Weed suppression
Vines and leafy plants can help shade the soil and suppress weeds for plants that have less dense foliage. This means less resource competition for your plants and less weeding for you.
4. Pest reduction
Some plants deter pests of other plants, making them an effective biological repellent. Others simply mask the scent of other plants, making them difficult for pests to find.
Tall plants can provide shade for those that need protection from too much sun and heat. By taking advantage of this benefit, you might even be able to extend the growing season of cool-weather crops.
6. Moisture retention
While taller plants shade shorter plants, those shorter plants shade the soil, preventing water evaporation and cooling the soil on hot, sunny days. These leafy, low-growing plants effectively act as a “living mulch.”
7. Beneficial habitat
While some plants repel pests, others attract beneficial insects that pollinate crops and feed on insect pests. Thus, planting these flowers can encourage increased fruit production (through pollination) and decrease pest populations (through predation).
Tips for Growing Fruits, Vegetables, and Herbs Together
What vegetables should not be planted next to each other?
When practicing companion planting, it is important to know which plants grow well together and which do not. Some plants can actually hinder the growth of certain other plants and thus should be located in another part of the garden. Additionally, plants that compete for the same resources and those that share pests and diseases should generally not be planted next to each other.
The guides linked to at the end of this article detail poor companions for specific plants, but here are a few examples of vegetable combinations to avoid:
- beans and alliums
- brassicas and tomatoes
- carrots and fennel
- cucumbers and potatoes
- watermelon and mustard
What vegetables and flowers grow well together?
Many vegetables, herbs, fruits, and flowers grow well together, as detailed in the individual guides linked to in the list at the end of this article. You have likely heard of the traditional “Three Sisters” garden, in which corn, pole beans, and squash grow together. The corn serves as a support for the pole beans, which fix nitrogen in the soil, and the squash acts as a living mulch.
Flowers often provide many benefits in the vegetable garden. Here are a few winning combinations of flowers and vegetables:
- marigolds and beans
- borage and tomatoes
- chamomile and brassicas
- nasturtium and squash
- sunflowers and cucumbers
- amaranth and melons
How close do companion plants need to be?
Instead of planting large groupings of one type of plant, mix companion plants together. For instance, a mass planting of one type of vegetable acts as a beacon for pests, while interplanting beneficial flowers and herbs with that vegetable will mask it and deter pests.
Companion planting often relies on planting two or more types of plants in close proximity. However, flowers that attract beneficial insects do not always need to be right next to the target plants for those plants to receive benefits.
Determining the proper spacing for two different plants grown together can be difficult, as it will really depend on the plants in question. For example, pole beans can be planted right at the base of corn and sunflowers, since they will use the stalks as supports. Nasturtium and squash, on the other hand, will need to be spaced apart so they don’t crowd each other.
In such cases, you can use the average of the spacing requirements of the two plants. If one plant requires, say, 12-inch spacing, and the other 6-inch spacing, leave 9 inches between the two.
Common companion planting mistakes to avoid
Perhaps the biggest companion planting mistake is planting the wrong plants next to each other. Trial and error is an excellent teacher, but the individual companion planting guides below will help you avoid planting incompatible plants together.
Additionally, avoid placing plants that share the same diseases and pests together, which can encourage the spread of those problems. Planting them together for a season might be okay, but definitely don’t follow one with the other the following season. For example, you can grow tomatoes and peppers in the same bed one year, but plant them in another bed the next year.
Also, while intercropping tall and short plants often works advantageously, keep in mind the sunlight requirements of the shorter plants. If they require full sun, the shade from the taller plants might stunt their growth. In fact, it’s a good idea to check the compatibility of the growing requirements of any plants you plan on growing in close proximity.
Best Companion Plants for Vegetables, Herbs, and Fruit
The following three lists link to individual guides on the best companions for different types of vegetables, herbs, and flowers. To help you find what you’re looking for, each list is sorted alphabetically. These lists are being added to constantly, so keep checking back to see what’s new!
Vegetable companion planting
A peppery salad green packed with nutrients, arugula makes an excellent addition to the vegetable garden. Grow companion plants nearby to encourage healthy growth and improved flavor for fresh salads throughout spring and even into summer.
Asparagus, strawberries, rhubarb, and horseradish make up a winning combination for a perennial food garden. Learn how to successfully grow these together and which annual plants you can also include to improve your asparagus harvest.
Companion plants for beans
Companion plants for beets
Companion plants for broccoli
Companion plants for cabbage
Companion plants for carrots
Companion plants for cauliflower
Companion plants for celery
Companion plants for corn
Companion plants for cucumbers
Companion plants for eggplant
Companion plants for garlic
Onions are wonderfully versatile vegetables in the kitchen as well as in the garden, as companion plants. Learn which vegetables, fruits, and herbs grow well with onions and which to avoid.
So many plants grow well alongside peppers, we couldn’t fit them all on our list! We did include the four plants to avoid growing with peppers so you know what not to do, as well as 16 of the best companions for peppers to get you started.
Companion plants for squash
Companion plants for strawberries
Struggling with ravenous tomato hornworms or pesky whiteflies? Before you reach for insecticides, consider planting herbs. Learn which herbs – and other plants – grow best alongside tomatoes in this handy guide.
Companion plants for zucchini
Herb companion planting
It’s delicious and easy to grow, and it repels many common garden pests, including mosquitos. Yep, I’m talking about basil. Read this helpful guide to learn how to make the most of basil in the garden.
Companion plants for cilantro
Companion plants for dill
Companion plants for echinacea
As an attractive flowering herb, lavender has a place in both flower beds and herb gardens. Learn which other herbs and flowers grow beautifully alongside lavender for a lovely as well as a practical pairing.
Flower companion planting
Companion plants for azaleas
Companion plants for coral bells
Companion plants for daffodils
Companion plants for dahlias
Companion plants for daylilies
Companion plants for dianthus
Echinacea, or purple coneflower, is both a beautiful native wildflower and a medicinal herb. Grow it with complementary plants for a stunning wildflower garden, or even interplant it with vegetables.
The showy flowering spikes of foxglove make it a classic cottage garden plant. Check out these tips for pairing this beautiful but toxic biennial with other plants in any garden.
The exotic red flowers of fuchsia make a stunning addition to any garden. Find out which other shade-tolerant plants grow well with fuchsia and may even help encourage healthy growth.
Gardenias adorn the garden with glossy foliage, elegant flowers, and a pleasant fragrance. Help your lovely gardenias thrive by growing some of their companions nearby.
Companion plants for geraniums
Companion plants for hibiscus
Companion plants for hostas
Companion plants for hydrangea
Companion plants for iris
The classic rose is beautiful but, unfortunately, rather fussy. Check out this list of flowers to plant with roses to not only complement their beauty but also encourage healthy growth.