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What is companion planting and what are the benefits?
Companion planting is the art of maximizing the space in your yard, containers, garden, or farm by planting a diverse mix of plants next to each other for a more productive and ecologically beneficial growing space.
Popular examples of companion planting in the garden include the salsa bed that includes planting tomatoes, peppers, basil, cilantro, and onions together to make a great salsa when harvested. Or the tomato sauce bed that includes planting tomatoes, basil, and onion together to make a great tomato sauce.
Companion planting requires some background research, but it does not require more labor or materials than seeding only one or two plants. By planting multiple plant families together, the plants can work together to build a healthy ecosystem in the soil. These planting partnerships often inspire gardeners when they see plant diversity in a prairie, forest, or even in their own yard.
An example of a great incidental companion planting is when a clover is randomly growing under a tomato or sweet corn plant. Even if it was not intentionally planted there, the clover is helping their neighboring tomato and or corn plant by supplying them with nitrogen that has been fixed from the atmosphere into the soil as usable nitrogen through a special mutualistic relationship clovers and other plants in the bean family have with a bacteria called rhizobia.
Remarkable results have been shown when growers plant bush beans alongside their peppers, tomatoes, and corn because of that reason. A lot of other plants have other mutualistic relationships in the soil that make them resourceful neighbors to most plants they are planted next to. Another example are onions and carrots, or any plants in the onion and carrot families. These plants have a unique mutualistic relationship with beneficial fungus in the soil. The fungal network helps supply them with water and nutrients in exchange for sugars that the plants produce through photosynthesis.
There are so many opportunities for companion planting with not just vegetables but also with flowers. Adding flowers to a garden bed, a container, or on a farm row with vegetables or herbs, brings depth, pollinators, and beauty.
Drawbacks
Where there are benefits, there are also drawbacks to companion planting. Some plants are not very neighborly to other plants. For example, onions have unique anti-bacterial compounds that make it appealing for beneficial fungus, but not for bacteria. This is great to ward-off bacterial pathogens, but not great for beans and legumes that rely on beneficial bacteria to fix nitrogen. Onions that are planted within a couple of feet of beans will negatively affect the bean’s ability to attract bacteria and not let the plant reach its full potential.
Planting variables to consider
There are planting variables to consider when companion planting. To begin, a grower must consider the height and width of every plant they are planting at the plants’ maturity to be sure they are leaving enough room for everyone.
Some plants prefer partial shade like lettuce, beets, carrots, collard greens, broccoli, and cauliflower. A grower can use this knowledge to plan their campion planting area and create that partial shade by planting taller plants like tomatoes, okra, and trellised cucumbers. Taller plants also create microclimates in their shade, keeping the soil cool for leafy greens and herbs like parsley and chives.
Another critical point about plant height is keeping smaller, sun-loving plants in front of taller plants so not to block out the light. This can also create a microclimate of warmth in front of the tall plants facing the sun, warming up the soil for seeds to germinate quickly.
Knowing the number of days until a plant reaches maturity is useful before planting. A grower's tip is to stagger the days to maturity of the seeds/transplants you are planting so you can get a continuous harvest throughout the season as well as to avoid shading out neighboring plants. An example is to plant sweet corn in late May, and then plant the neighboring pole bean three weeks later. By giving the corn a head start, the corn will have a long enough stalk for the bean to latch on to by the time the bean is ready to climb. This method will also allow the grower to harvest the beans before the corn ears are mature.
Is direct seeding or transplanting better for companion planting?
A grower can do both! In the video accompanying this blog, we direct seed vegetables and flowers in a garden bed with nice sun exposure until the midafternoon. The morning sun can quickly warm up the soil in the morning and let the seeds get a jump-start on germination.
Direct seeding, also known as direct sow, is planting seeds directly into the soil. In the video I make small trenches or holes in the soil for the seeds to go into. The seeds are planted by hand, the soil placed back on top of the seeds, and the soil is then pressed down making sure the soil is firm before getting the hose and watering the seeds. It is important to check your Harris Seeds seed packet for how deep in the soil you should plant the seeds you purchased.
Direct seeding is a fun and interactive activity that everyone of all ages can enjoy, especially children. However, be prepared when seeding with kids to have a more randomized approach to your garden. The success rate is excellent with this approach but goes against the routine of most adults. Have fun!
What plants can I use with companion planting?
Direct seed is the best way to get a more diverse set of plants in your garden. While certain plants do well as transplants, (like tomatoes, peppers, angelonia, and geraniums to name a few), many plants prefer being direct seeded. Flowers are a splendid way of using the direct seeding method in your companion planting bed. Flowers and ornamentals, especially sprinkling in some native varieties, are so important for bringing in pollinators and beneficial insects that, in turn, help their neighbors.
Sunflowers, zinnias, cosmos, bachelor's buttons, calendula, and amaranth are just a few of the many flowers that prefer to be direct seeded into the garden, rather than transplanting, and all of them make wonderful companion plants for your vegetable or herb garden. Tucking in a few zinnias alongside your tomatoes is a wonderful way to encourage more pollinators to visit your garden. The nectar rich flowers will draw in a wide variety of beneficial insects, especially butterflies.
Our resident Farmer Florist and Ornamentals Product Manger swears by companion planting cosmos with squash and tomatoes. More pollinators visit the cosmos and in turn visit the vegetable blossoms creating a more bountiful harvest. If planting in rows, consider companion planting a flower every third squash or tomato plant. For raised beds, container gardens, and landscaping, work the flowers into your normal design or layout. Even if they are not planted in the same bed, being near your vegetables will benefit them.
Companion planting is a fun and adventurous way to plant out a garden, farm, or container garden, and direct seeding is a wonderful way to get it started. Companion planting may take a little more thought and effort, but it will turn out to be a fulfilling process after you see all the color, pollinators, and insects buzzing around. Not to mention, planting with a diversity of plants and plant families reduces pest and disease pressure by promoting soil health and therefore plant health, and a diversity of beneficial insects will limit the population of insect pests.
I hope you give companion planting a try and enjoy it as much as we do here at Harris Seeds. Shop our favorite direct sow seeds. Happy Planting!
Drew Hundelt
Product Manager & Content Specialist
Since stepping foot on his first urban farm in 2012, Drew found a passion that would eventually lead him here at Harris Seeds, Garden Trends Inc. Growing in multiple environments ranging from western New York to the bay area of California, and many environments in between, Drew has been and continues to build food production systems that yields food and community. Drew’s favorite projects so far in his career include carrying out a 12-acre trial of regenerative winter wheat production in western Pennsylvania and creating a horticultural program with three acres of market gardens, food forests, and greenhouses in the urban landscapes of Denver.
