If you use organic practices in your garden, you know the struggle of not only growing great food, but also battling pests and diseases along the way. The long-term payoffs to ourselves and our environment are well worth the effort of organic gardening, but we don’t want to give the impression that it’s easier than it is! Sometimes it can feel like you’re working against your environment, rather than with it. Well, there are a few steps you can take that may serve you, your garden, and your harvest in the long run. These steps fall under the umbrella term companion planting. 

Companion planting is the practice of planting different crops near each other that help each other grow. Depending on the pairing, the league can tackle pests, nutrient requirements, pollination needs, or maximizing space! Especially helpful for those of us with limited growing space. The benefits of companion planting are wide reaching, but the practice can easily become a natural part of your garden planning routine. 

What is Companion Planting

Companion planting is the practice of pairing crops together to support each other's growth in some way. Many companion planting pairings are largely anecdotal or folkloric. This does not mean that these pairings have no agricultural value - the opposite in fact! Often these practices work better or differently depending on the conditions but they are easily replicable and you can see how they perform in your own gardens. As you collect this information, you can pass on the knowledge and widen the pool of independent information that growers have access to. While there is a lot of competing information out there, it never hurts to try something new. Companion planting is based on the understanding that gardens function best when they are diverse and interactive; in other words, when they function like ecosystems! When you are companion planting your vegetables, you’re adding diversity to your garden which makes it stronger. 

A common companion planting practice that you may know of is the Three Sisters. This is a three-crop planting method involving corn, pole beans, and squash. This practice comes from indigenous farming practices and it’s important to note that this practice was used in Indigenous communities all over the Americas. These crops offer support to each other in a number of ways. The corn acts as a trellis for the pole beans (cutting down on your labor), and the beans (and all legumes to varying degrees) fix nitrogen. They assist with providing nitrogen to the corn which requires quite a bit of fertility to produce ears. The squash is a low-growing ground cover with large leaves that shades out weeds, preserves moisture, and protects the beans and squash from larger pests. There are clear connections in this example of how these plants work together to create a beautifully functioning polycrop. 

Companion Planting Benefits: The Why and How

Companion planting can benefit your garden in many ways. The root of its benefits lies in the diversity of the garden. But, when you’re making decisions about what to pair together, you may consider one or all of the following benefits and how they interact with and support each other. 

Pest Management

Companion planting for pest control can easily become a natural part of your garden routine. The secret lies in hiding your most vulnerable crops among other plants with strong smells and planting these crops among a diverse array of flowers and herbs that will attract beneficial insects. Many beneficial insects not only support pollination and your harvest, but also will feed on your most troublesome pests. 

Attracting Beneficial Insects for Pest Control

For instance, the parasitic wasp - very friendly to humans, even if the name suggests otherwise - loves to collect nectar and pollen from dill, cilantro, and fennel blooms. Parasitic wasps are useful in the garden in a variety of ways, but most famously they’ve been known to lay their eggs inside the tomato hornworm. This results in the hornworm dying, hopefully before it's able to decimate your tomato plants. This also means that parasitic wasps will be born in your garden again - with plenty of food to feed on! This protects your other pests and can also mean a multigenerational neighborhood of parasitic wasps will live in your garden for years to come. Luckily, if you leave your cool weather herbs like dill, cilantro, and fennel to go to seed, they’re sure to flower just in time for your hornworms to become a problem. This kind of lifecycle happens entirely on its own in the wild. All it takes from you is to not pull out your cool weather herbs when they begin to bolt. Leave them be and thank them later! 

Deterring Pests Using Companion Plants

In other situations, you may use certain plants to camouflage your pest-prone crops. Aromatic herbs like rosemary, lavender, sage, thyme, etc. are often used to repel certain pests. They aren’t attracted to the strong scents which can discourage them from sticking around long enough to go after your crops. A combination of these methods can result in a reasonable management system for your organic pest control this year. 

Pollination and Biodiversity

Do you ever feel like you’re getting really low yields and can’t figure out why? The issue might be pollination. Lots of plants require pollination in order to produce fruit. If you’re not hand pollinating, then this transfer must happen naturally. Not only that, but most flowers have to be visited by pollinators several times in order for full pollination to occur. If this doesn’t happen adequately, also referred to as incomplete pollination, it can result in misshapen fruit, low yields, or rot. If you’re able to offer enough of what a pollinator needs - food, water, and shelter - you’ll be able to attract pollinators. Growing an abundance of flowers and herbs will bring all the boys to your yard! The key to companion planting is the diversification of your garden. That makes companion planting for pollinators extremely easy. There are a few things you can do to really capitalize on it! 

Times of Day

Pollinators will be most active at different times of day depending on their species. Bees tend to be most active in mid to late afternoon. Hummingbirds can be spotted in the early morning and early evening. Bats, which not only pollinate but also eat mosquitos, are nocturnal and come out at night. Your array of flowers and herbs should take this into consideration. If you only grow moonflower and primrose, your afternoon bees may be found wanting for food! Offer a wide array of flowers and herbs that open and close at all times of day. With enough diversity, you’re unlikely to leave anyone hunting for food - except your pests! 

Native Plants

The traditional European honeybee makes a great pollinator, but nothing is quite as good as our native bees and pollinators! The best way to support these populations, which are indeed waning, is to grow native plants. Many native plants are flowering and also have aromatic compounds that can offer the same or similar benefits to non-native herbs and flowers. There’s no need to choose one or the other - grow both native and naturalized plants in your companion planted garden! 

Diversity Tip

When deciding what wide array of plants to plant in your garden this year, take care to consider if anything you’re planting is invasive in your area. It’s great to have an abundance of plants but if something is being planted in your garden - especially if it’s in an area that isn’t at the top of the list to maintain, like a wildflower plot - that is considered invasive in your state, consider planting something else! Invasive plants left to go wild cause more long term damage to the diversity of your garden, and ultimately the benefits of companion planting. 

Soil Health and Nutrient Exchange 

Companion plants can be used strategically to improve soil health over time. It’s not as simple as a one to one exchange, but as you get used to the patterns, you’ll start to notice the benefits. 

Soil Health 

Companion planting can be used to improve soil health in a number of ways. Certain crops that have deep tap roots like comfrey, daikon radishes, or dandelions can aerate soils and improve oxygen availability and soil compaction. Lush and compact growth habits as a result of companion planting can help shade the soil which inhibits the germination and growth of weeds as well as holding in soil moisture. Diverse plant life requires a diverse array of nutrients. While your garden soil will still benefit from compost and organic amendments, you are at less risk of one major nutrient being completely depleted. Studies have shown that companion planting can increase the nutrient cycling activities and, in some cases, microbial diversity occurring in our soils. 

The Truth About “Nutrient Exchange”

Some folks will describe the relationship between carrots and peas for instance. The two crops have two completely different growing patterns, so they don’t bother each other in the garden. Further, it’s said that carrots, thanks to their deep tap roots, can pull up calcium and potassium that the peas’ roots aren’t able to reach. Peas, in contrast, fix nitrogen as they grow, which the carrots can then use. This isn’t an accurate description of the process because, while both of these things do happen, the crops aren’t necessarily sharing the nutrients with each other. That being said, the benefits of space efficiency that they offer as a partnership are very real. And if the carrot tops and leftover pea vines, assuming they’re free of diseases, are chopped up and left to decompose - the aforementioned nitrogen and calcium are available for future plantings. Not to mention that the tap roots of the carrots further aerate the soil, making oxygen more available and soils looser so that future iterations of root crops can develop more efficiently. 

Using Space Efficiently When Companion Planting 

Efficient use of space when companion planting is a result of considering the different traits of your crops and matching them up based on a number of factors including growing season, root structure, size, and harvest time. The very basic benefits of this are apparent in an example like lettuce and garlic. Garlic grows in your soil for nine months, taking up valuable real estate. Garlic is, as we know, a root crop that develops its bulb in the spring. Intercropping with lettuce, which has very shallow roots, during the cool spring temperatures saves space that otherwise would not be planted in until your garlic is harvested in June or July. The shallow roots means the lettuce doesn’t disrupt the garlic’s development. The leaves also help to conserve moisture in the soil and inhibit the germination of weed seeds as the temperatures warm. These are the two major concerns of the spring season for garlic and so these two crops make a perfect match! 

Historical and Cultural Roots

The most famous iteration of the companion planting is that of the Three Sisters, corn, beans, and squash. During the process of domesticating these crops, indigenous growers of the Iroquois observed that the crops performed especially well when grown together. This technique would have come together between eight and ten thousand years ago. Around two thousand years ago, authors in Greece and Rome were observing allelopathy in other plants, particularly bay trees and walnut trees. There are even signs of companion planting in rice fields in China with mosquito ferns, which host helpful bacteria and block light to halt the germination of competing plants. Most cultures have historical evidence that their growers knew that diversity in the garden was the key to a healthy garden ecosystem. 

Companion planting may not be able to offer you a direct and surefire path to a successful harvest, but from today’s experiences and those of our predecessors, we know that diversifying our garden is the key. There are simple and advanced ways to integrate companion planting into your garden. 

Modern Companion Planting Practices

Today, companion planting is wrapped up into our gardening culture in a number of ways. From comprehensive gardening praxis with certifications and the whole nine yards to simply taking advice from a neighbor - you can implement companion planting in your garden. 

Permaculture

Permaculture is a style of land management that centers how an ecosystem operates. There are design principles and styles of thinking that guide those looking to implement permaculture. It’s not only relevant in the garden! Permaculture principles can be utilized in home design, city planning, or even rewilding. Companion planting is a common technique utilized by permaculture gardeners. 

Biodynamics

Biodynamic farming is a method of agriculture that emphasises spirituality and relationship to nature. In fact, one of its core tenants is that soil fertility, livestock, and plant life are all interrelated and should be treated as such. The methods it totes, such as burying a cow horn in the ground with quartz and compost to harvest cosmic forces, can be a bit out there for a lot of gardeners. However, in practice, taking extra steps to think about the interrelations of the parts of your garden and honor what it gives you every year can be beneficial to our long-term relationships to the garden, our observations over time of what works and what doesn't, and the way we think about the environment around us. While the phrase companion planting isn’t commonly used among biodynamic growers, biodiversity is a key part of biodynamics, and companion planting contributes to that. 

Oral Tradition

The most common, accessible, and trial and error form of companion planting! There are endless crop combinations that have been passed down through the oral traditions. Whether it’s cultural, generational, or simply neighborly - most growers are bound to have been told at one point or another, “You should plant ____ with ____.” The oral tradition doesn’t have a class, or a certification, or anything else official. In fact, some of what is passed down orally is explicitly not a good idea to try! But as with all gardening processes, it’s a question of experimentation, trial and error, and trust. 

Using Trap Crops

Trap crops are an essential method of companion planting but operate in a different way than other planting pairs do. Trap crops are planted in your garden with the main purpose of attracting pests away from your main crop to decimate the trap crop instead. Why would you plant a crop just to wish for it to fall to pests? Because your trap crop is a lot easier to grow and quicker to mature than your non-trap crop. 

When considering a trap crop, you’ll want to consider the pests that you struggle with the most. Cabbage loopers on your broccoli, flea beetles on your eggplants, aphids on your beans, so on and so forth. What other crops would these pests love that will also mature faster, or that you can start earlier than your broccoli, eggplants, and beans? 

Trap crops are especially useful when they are flowering or going to seed. Some common trap crops are radishes, nasturtiums, and kale. Radishes can mature in less than a month and go to seed quickly, especially in the summer heat. They make a great snack for flea beetles. Nasturtiums attract a ton of aphids, which can distract your resident garden population from your other crops they may love. Kale is one of the more quickly maturing brassicas and will appeal to cabbage loopers. If you can get your kale established before your broccoli and cabbage, you can trap the cabbage moth larvae on the kale and keep it there. These are all things you should consider when planning to use trap crops. Studying up ahead of time can result in more success in your garden. 

Trap crops should be planted eight to 12 feet away from the crop you’re trying to protect. Ensure that they will be available to your pest at the height of their egg laying or munching or whatever their problem lifecycle stage is. As an added measure, consider protecting your desired crop with row cover until your plant, if fruiting, starts to flower and needs to be pollinated. Once your trap crop is good and infested, remove the crop from your garden - taking the adult bugs, larvae, and eggs with you away from your desired crop. This removes a portion of the pest population from your garden!

Companion Planting Partners

While we know that companion planting is not a straightforward, research-backed technique, we also know that diversity and gardener experience are essential in the garden. Here are some well-loved garden companion duos in a comprehensive companion planting chart. 

Best Companion Planting Combinations

Some of our personal favorite companion planting combos to try in your garden this summer:

Tomatoes and Basil

Tomatoes and basil perform beautifully together in the garden. As tomatoes spread and vine out in the vertical space, basil enjoys the cool understory of the tomato forest. The shade helps them to keep from getting burnt by the intense summer sun. Not to mention, when you harvest the one, don’t you want some of the other? Pizza, anyone?

Corn, Beans, and Squash

The most famous companion planting combination of all! Don’t take our word for it. Try it out in your garden this summer and learn from the Indigenous growers that came before you. 

Carrots and Lettuce

Truly a match made in heaven. Your sensitive carrots will appreciate the gentle support from non-intrusive lettuce in the garden this spring. Carrots are sensitive to moisture levels and weed competition. Lettuce has shallow roots, takes up very little space, shades out weeds, and is harvested just when your carrots are able to stand on their own. 

Companion Plants to Avoid

There are a few planting combinations you should avoid. Just as certain crops thrive together, certain crops do not thrive when grown together. These plants are simply incompatible because of their nutrient needs and disease susceptibility. 

Another incompatible planting combination that you’ll likely come across is planting allelopathic plants with other crops. Allelopathy is the chemical inhibition of one plant by another. These are plants that release certain chemicals into the environment, most often the soil, that act as germination or growth inhibitors. A great example of this is the Black Walnut tree (Juglans nigra). These trees contain juglone, which often kills plants growing nearby, most notably nightshades such as tomatoes, peppers, potatoes, and eggplants. Some other plants that are thought to be allelopathic are goldenrod, sunflowers, and ryegrass.

How to Plan Your Garden

You may be accustomed to making a garden plan every year, but to integrate companion planting into this season’s plan, there are a couple things you should consider:

How to Create Your Companion Planting Plan

First we start by asking ourselves the important questions.

What do you want to grow? 

What crops do you want to actually harvest this season? Consider planting time, growing season, your growing zone, etc.

What are your biggest battles in terms of pollination, pest control, or nutrient availability?

Have you grown these crops before? Do you know what issues you face when you do? Or have you had issues in the past with different crops that need to be addressed in future growing seasons. Either way, consider what you want to address.

What are their ideal plant companions? 

What should you plant alongside your desired crops that address the issues you identified above? Think about the time of year these issues may arise, for example, you need to attract pollinators while your main crop is flowering, which means you’ll want to choose a companion that will flower and attract pollinators at that time. 

What should they not be planted next to? 

Are there garden antagonists that you should plan to plant away from one another in your garden beds? 

What are the planting distances of each of these crops? 

Companion planting doesn’t mean we get irresponsible with our planting distances. While your companion vegetables, flowers, and herbs may not need to be harvested or need the space to reach full size, your harvestable crops will still need space to grow and spread. Take this into account when considering how much of each of these plants you can actually grow. Companion planting can reduce your planting space in small ways, but shouldn’t cut your garden space in half. Plant your companions in between rows or around borders to keep them inconspicuous. 

Mapping Your Garden Beds

Mapping out your garden beds is a great way to make sure you don’t overspend on plants or seeds this growing season! Figure out exactly how many plants or how much seed you need for both your harvestable crops and their companions. 

Source Your Seeds

Open-pollinated seeds are a great match for companion planting. The values associated with companion planting, increased diversity, and overall garden wellness are deeply compatible with open-pollinated seeds. Sow True Seed has everything you need from seeds to crowns and bare roots for your companion planted garden this season. 

Tips for Success When Companion Planting

Companion planting may seem confusing at first, but after a few seasons of getting in the habit of it, it’ll come as naturally as planting a seed does in spring! 

Timing

Companion plants - particularly for pest control and pollinators - are especially helpful when they are flowering and going to seed. Consider the timing of your planting ahead of your main crop planting to ensure that when the pests come, the trap crops are looking extra attractive to both the pests and the beneficial insects that feed on them. 

Spacing

Companion planting doesn’t mean our crops don’t require space. Ensure there is enough airflow between plants to limit the spread of disease and for your harvestable crops to reach their full potential.

Crop Rotation

Crop rotation should be a regular part of your garden planning routine with companion planting included. Never plant the same species in the same bed two years in a row - or even three to four if you can manage it. This will help your companion planting pairs do the best work they can! 

Allelopathic Plants

Sunflowers and black walnuts are two common plants that have allelopathic properties. This means they will stunt the growth of nearly anything planted nearby. Take care to distance your crops from these plants in your garden.

Getting Started

Ready to get growing? Try companion planting in your garden this year. Even if you just start with a simple combination like tomatoes and basil - you’ll soon enough have a host of helpful herbs and flowers to accompany your harvests! Get started by browsing the vegetable, herb, and flower seeds available at Sow True Seed.