Like humans, good plant companions bring out the best in each other. Throughout the forest, certain plants need the same resources and will cause competition between plants. In contrast, companion planting ensures plants are good neighbors, supporting each other instead of clashing. As an example, look to nature, where smaller plants take shelter from taller trees. In the gardening realm, this means equitably sharing nutrients and upholding each other, in a very literal way. It also means improving the health and overall yield of individual plants. When it comes to your garden, think about partnering up some classics that will benefit your landscape and your favorite garden-fresh recipe.
Benefits to companion planting
Choosing the right plants to combine in a space means being able to use every square foot. Intercropping results in lower plants growing upward by using taller plants as support. It also means different plants aren’t fighting for the same resources, so while carrots grow underground, an adjacent and shallow-rooted lettuce won’t infringe.
In addition, appropriately matched companion plants will provide insect control for the entire space. Similarly, many flowers attract desirable insects (like bees!) that can help out in the garden, naturally. For example, carrots, dill, parsley and parsnip attract beneficial insects like praying mantises, ladybugs and spiders that dine on problem insects on other garden plants.
Other benefits of one plant to another include natural shade protection, weed suppression and healthier soil.
The famous trio — The Three Sisters
Any book on companion planting will mention a Native American discovery known as “Three Sister Planting.” This trio brings together corn, beans and squash and serves as a perfect example of the power of companion plants. The corn, tall and sturdy, supports the beans below that naturally climb the stalk. The beans, like all legumes, balance nitrogen in the soil, which feeds the corn. Meanwhile, the squash, often in the form of pumpkins, quickly develops large leaves that provide shade and natural weed-blocking for both the beans and the corn.
Companions to popular spring crops
Here are some excellent suggestions for what to pair with the most popular plants going in the ground this spring.
When you get the tomatoes in the ground, surround them with dill and basil to protect them from invasive hornworms. Lots of crops partner well with tomatoes, including asparagus, beans, carrots, celery, lettuce, melons, mint, onions, parsley, peppers, radishes, spinach and thyme. As you move through the seasons, replace the cool weather, early season options with those that perform better during the summer heat.
Although you don’t want to put cabbage next to tomatoes, they do have several companions in common. Intermingle sage to deter cabbage moths. Also add in beans, celery, cucumbers, dill, kale, lettuce, mint, onions, potatoes, spinach and thyme as the weather and seasons allow.
Radishes are quick-growing, cool weather veggies perfect for spring planting. Radish is also a great partner for other garden inhabitants, because it grows underground. Common radish companion plants include basil, beans, carrots, cucumber, coriander, lettuce, melons, onions, peas, spinach and tomatoes. Keep radishes away from kohlrabi and hyssop.
All leafy greens appreciate the cool days of spring and start to struggle with the heat that summer brings. The many varieties of lettuce partner well with just about anything else you’re able to plant, and some plants will even keep lettuce shaded and cool enough to extend its season a bit. Good garden neighbors for lettuce include asparagus, beets, Brussels sprouts, cabbage, carrots, corn, cucumbers, eggplant, onions, peas, potatoes, radishes, spinach, strawberries, sunflowers and tomatoes. Just keep lettuce away from broccoli.
Snow, snap and string peas also excel in a spring garden, especially when paired with beans, carrots, corn, cucumbers, radishes and turnips. Do not allow peas to share garden space with onions and garlic.
Onions and garlic
Like co-workers after a garlicky lunch, these plants deter a wide range of pests. Even with their notoriously strong statement as a vegetable, the plants are mild and friendly with most garden neighbors. The exception is beans and peas, which are stunted when paired with onions and garlic.
Avoid putting potatoes next to sunflowers. Otherwise, they are fairly happy in any neighborhood. They do especially well when coupled with beans, cabbage, corn, eggplant and peas.
Overall good neighbors
There are some plants that are generally seen as good neighbors to everyone. As pest control, marigolds are universally acknowledged for the ability to repel nematodes, a particularly aggressive little bugger. Nasturtiums, in contrast, draw aphids toward them, keeping the insects from munching down nearby tomatoes, lettuce, kale and cabbage.
Although toxic to livestock, tansy can be a welcome addition to the garden as a repellent for cutworm, which can decimate asparagus, bean, cabbage, carrot, celery, corn, lettuce, pea, pepper, potato and tomato plants.
Many herbs including catnip, hyssop, rosemary and sage will scare off the cabbage moth, an enemy of crops like broccoli, cabbage, cauliflower, kale, turnip and radish.
Also note that you can improve your pest control by avoiding planting large groupings or rows of the same type of vegetable, which can serve as a bullseye for problematic pests.
In addition to balancing out each other’s needs, companion plants work together to provide the greatest yield in the smallest space. Efficiency and organization in your garden means placing quick-growing spring selections like lettuce, spinach, radishes, swiss chard and carrots in between the early buds of long-season crops like melon, pumpkin and squash. With this technique, the quick crops will be ready for harvest before the sprawling plants need more real estate to grow.
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