Companion planting is a type of polyculture. For a long time, this has been the most widespread form of agriculture. While it has lost its popularity in the last century, its environmental and health benefits are helping it make a comeback.
Companion planting can be very beneficial to industrial agriculture, although it can be hard to put in place on a large scale. On the bright side, it can be easy to apply in a small environment. This gardening practice can bring many benefits to the average gardener who is looking to maximize their garden space and the quality of their crop.
Keep on reading to discover the history and the advantages of the agricultural practice known as companion planting. We also have some suggestions for the best plant combinations to start with, as well as some tips that will help you get the best results.
History of Companion Planting
This agricultural strategy has been used since ancient times, but its history is not well documented. Specialists believe that it dates back to antiquity. The Greeks and the Romans were using it intensively 2000 years ago. Nonetheless, it is most likely that this practice has its roots in the origins of agriculture.
It is very probable that this practice started when people noticed that certain plants inhibited the growth of other plants. Through the process of allelopathy, some plants secrete biochemicals in the soil. This helps the plants thrive, but those biochemicals can affect other plants negatively. The Romans documented this knowledge in writings more than two millennia ago.
The Chinese have also been using companion planting for at least 2000 years. The most common example is the use of mosquito ferns in combination with rice crops. The ferns fix nitrogen from the air and block the sunlight for other plants that might compete with the rice.
The oldest known example of companion planting comes from Indigenous Americans. They have been using this technique for about 10,000 years.
- Their most popular planting method is called the three sisters and it consists of a mixed crop of beans, squash, and corn.
- The corn is planted first.
- Once it reaches a few inches in height, you add the beans and the squash.
- Just like the mosquito fern, the beans do an excellent job capturing nitrogen from the air and fixing it in the soil.
- The nitrogen helps the corn thrive and the squash keeps weeds at bay. In turn, the corn gives the beans and the squash something to climb on.
So, if you’re planning on growing squash, beans, or corn, you can give this method a try.
Over the years, more and more people noticed that the richer an environment is, the better it will naturally support itself. A relevant observation on this point was once made by Charles Darwin. He noticed that two neighboring villages were having different results in their hay crops.
After a quick analysis, he concluded that one village was yielding better crops because it had more old ladies who were keeping cats as pets. The conclusion might seem peculiar, but there is a very logical explanation to it. Cats eat mice. It is a known fact that red clover improves the quality of hay crops. Well, the main pollinator for red clover is wild bees and mice are the main predators of wild bees. As we all know, cats are the main predators of mice. As such, by keeping cats as pets, one village managed to create a more welcoming environment for their hay crops. It is quite a complicated theory, but very interesting!
Companion planting lost its popularity when we started using herbicides and pesticides in agriculture. Nonetheless, this polyculture practice made a comeback in the 70s. It was encouraged by the organic gardening movement. It did not manage to completely replace chemical-based agricultural practices. However, it slowly becomes a common practice in home gardens. How popular it will become depends mainly on consumer behavior and in our interest in growing organic food.
Advantages of Companion Planting
This practice has many benefits and it is very flexible. You can integrate it in various environments, regardless of the size of the space. If you are not convinced, here’s what makes it truly beneficial:
Low-growing plants are often used to keep weeds at bay. Such is the case of the squash in the three-sisters method and the mosquito fern in Chinese rice crops. Flowers and herbs are also commonly used in many vegetable crops because their strong scents repel damaging insects.
More beneficial insects
Flowers and herbs repel damaging insects, but they also attract beneficial insects. Diverse gardens that are rich in native herbs will always attract bees, ladybugs, and butterflies.
We already mentioned that plants change the biochemistry of the soil. While some plants are more selfish and only support their own growth, others enrich the soil to a degree that other plants can benefit as well. Such is the case of plants that fix nitrogen. There are also plants with deep root systems which bring nutrients up from the depths of the soil. This is very beneficial for plants with shallow roots.
It is no mystery that some plants thrive in the sun while others prefer shade. As such, bigger plants usually provide an excellent natural shade for low-growing plants. Moreover, low-growing plants can also decrease the soil temperature. This helps plants that like a colder environment for their roots.
Vines and other types of climbing plants need vertical support to expand. You can provide them with man-made supports, but they will grow better if they climb on the stems of taller plants.
Intermingled crops allow you to make the most of even the smallest gardening space. You can combine low-growing plants with tall plants. You can also combine plants with deep roots with plants with shallow roots.
How to Start, Best Plant Combos & What to Avoid
In a wild environment, plants with similar or complementing needs will naturally grow together. However, in a controlled environment, it is important to understand the needs of the plants to know how to combine them. To make things easier, we have put together a list of the most popular plants that people want to grow, along with their preferred companions. We have also included the natural foes of each of these plants.
All types of beans are great for fixing nitrogen in the soil, and they can be planted together with a wide variety of plants. They thrive when they are combined with radish, eggplant, potatoes, and cucumber. They also get along well with strawberries, beets, celery, radish, and peas. To repel pests, you can also combine them with marigolds and catnips. Avoid planting them with onions, peppers, and garlic.
Cucumbers enjoy sharing their space with beans, cabbage, lettuce, radish, peas, and tomatoes. They also make a good team with celery, corn, dill, and sunflowers. To repel insects, combine them with marigolds and nasturtiums. Avoid planting them next to melons, potatoes, and any aromatic herb.
Potatoes thrive when planted near cabbage and beans. They also do well with lettuce, spinach, radishes, and scallions. To repel pests and prevent diseases, plant some horseradish and petunias near your potatoes. Avoid planting cucumbers near raspberries, sunflower, cucumber, carrots, fennel, asparagus, and turnips.
Peppers like the company of eggplants, onions, and tomatoes. Carrots, squash, cucumbers, and radishes also make for good companions. Oregano, basil, parsley, and rosemary can deter pests away from your pepper crop. Do not plant peppers near beans, broccoli, or kale.
Carrots, cucumbers, garlic, and onions are great companions for tomatoes. Many aromatic herbs are also recommended. They don’t just deter pests, but they also improve the flavour of the tomatoes. Such is the case of basil, amaranth, bee balm, mint, chives, parsley, and lemon balm. Bad companions include corn, cabbage, dill, eggplant, peppers, potatoes, and fennel.
Carrots thrive when planted near beans, onions, lettuce, and peas. They also get along well with leaks and radishes. Rosemary and sage are great for deterring carrot pests. Avoid planting near dill, fennel, and parsnips.
An eggplant crop is considered high maintenance, but a few friendly companions will increase your crop’s chances of success. Plant eggplants with peas and beans to fix nitrogen in the soil. Peppers, tomatoes, potatoes, and spinach are also good companions. Thyme and French Tarragon will deter common pests. Avoid planting eggplants next to the fennel.
Beets thrive when planted next to onions, beans, lettuce, radishes, cabbages, and cabbages. Catnip is great for repelling non-beneficial insects. On the other hand, pole beans, field mustard, and wild mustard are natural foes for beets.
This nutritious leafy green will get along great with onions, beets, cucumbers, celery, spinach, and potatoes. It also enjoys the company of most aromatic herbs. We recommend planting it next to garlic, basil, mint, chamomile, dill, sage, rosemary, and thyme. Avoid planting it near strawberries, beans, or tomatoes.
Radishes enjoy the company of peas, lettuce, cucumbers, and beans. It also makes good friends with spinach, squashes, and parsnips. To repel pests combine it with nasturtiums. Avoid planting it next to kohlrabi.
Onions are easy to grow and they get along well with a wide range of plants. Ideally, you should pair them with broccoli, cabbage, carrots, lettuce, kale, peppers, and tomatoes. Dill, parsley, and mint will do great for repelling pests. Avoid planting onions next to beans and peas
These are a few important combinations that people apply when they want to grow organic food through companion planting. If you plan on growing other plants, make sure you do proper research to understand their needs and combine them with the right plants.
Tips for Companion Planting
Simply finding the right plant combinations is not enough for a successful mixed crop. You need to understand the specific needs of each plant to combine them in a way that suits the needs of the whole crop. Here are a few tips that will help you along the way.
Stop using pesticides and herbicides
Most pesticides and herbicides, even organic ones will also affect beneficial insects. Moreover, the purpose of companion planting is to stop using pesticides altogether, and it will be more efficient if you do this from the start.
Consider the growth behavior of your plants
It can be tricky to combine different plant sizes while keeping in mind the sun needs of each plant. For example, if you combine several sun-loving plants, you must place the tall plants on the north side. This way they won’t cast a shade on low-growing plants. On the other hand, if you have low-growing plants that prefer a shady environment, you can use tall plants to protect them from direct sun exposure.
Rotate crop locations
Certain parasites can survive in the soil in the cold season. If your space allows it, try to rotate your crops every year, to allow the parasites to die naturally. This is particularly important for cabbages. On the other hand, some nutrients left in the soil can be beneficial for other plants.
Allow some vegetables to flower
A vegetable that flowers is no longer good for harvesting. However, if it happens for some vegetables to bolt, don’t take them out. Allow them to flower completely. The flowers will attract beneficial insects that lay eggs. The larvae of those insects feed on plant pests.
Promote diversity in your garden
The key to companion planting is to combine as many compatible plants as possible. The more diverse an environment is, the better it will regulate itself naturally. Furthermore, the more diverse an ecosystem is, the fewer pests you will have to deal with.
Companion planting is very efficient for small crops. Nowadays, most people who grow their food want it to be as organic as possible and this gardening strategy is the first step in this direction. Aside from health benefits, it also helps you maximize your garden space and it keeps weeds at bay. It decreases pests, it decreases the chances of diseases and it attracts beneficial insects. You don’t need to be an experienced gardener to give it a try because this is the natural way in which plants grow in the wild.