Companion planting is a technique used in farming and gardening where multiple plant species grow together to improve aspects of cultivation. Planting multiple species together is a time-tested method that can increase product, promote disease and pest resistance, and improve space utilization. It is a form of polyculture followed for thousands of years. The earliest recorded instances of companion planting date back to indigenous Americans’ well-known “Three Sisters” plant grouping. This grouping allows the characteristics of each plant to benefit the whole mutually.
There are several ways that companion planting can benefit agriculture. First, specific groupings planted near each other, maximize space. Also, the close groupings of plants provide either structure for climbing plants or protection from the elements for more delicate plants, or both.
Next, certain groupings absorb nutrients that are crucial to the growth of their companions. For example, grouping legumes with other plants allows the legumes to fix nitrogen in the soil to the benefit of their neighbors. Deep-rooted plants can draw from a larger area than their shallow-rooted counterparts.
In addition, the sheer proximity of other plants can disrupt pests from attacking valuable plants. Strong-smelling herbs like basil can make it more difficult for pests to attack tomatoes. Perhaps somewhat more controversially, certain plants produce chemicals that can inhibit disease in their companion plants. There is much disparity regarding the efficacy of some of these claims but many believe strongly that these techniques are effective enough to be better than overusing chemical treatments. Certainly, when it isn’t necessary to have “beauty pageant” quality produce that just tastes good, there’s a lot to be said for these methods.
Note that there is also a list of plants that do not go together. Some of these are included in the lists below.
Top 10 Companion Planting Groupings
Here is a list of the top 10 groupings by popularity. There are *many* more groupings available across the internet and I will link to some at the end of the article.
Grow tomatoes with basil, asparagus and/or cabbage. Marigolds near tomatoes are said to be excellent at protecting tomatoes and other plants from numerous kinds of pests and diseases. Because of common pest species, avoid putting corn and tomatoes to close together.
Goes well with beans, peas, and cabbage. Nasturtium helps cucumbers fight pests when bunched together. Avoid putting the herb sage together with cucumbers.
Go with basil, onions spinach, and tomatoes. Keep vining beans away though or you’ll end up with a tangled mess.
Corn is one of the Three Sisters grouping (the other being squash). Others include cucumbers, cabbage, and celery. Keep away from garlic, onions, and shallots.
Beans, lettuce, peas, and peppers are friendly. Chives, rosemary, and sage improve flavor and pest resistance. Dill is a no-no as it retards a carrot’s growth.
Corn and beans make up the Three Sister triumvirate. Borage helps flavor while marigold and nasturtium improve bug resistance.
Onion plays nice with a lot of other plants. Check around the internet but the list is long. Best to keep away from peas and lentils.
Try beets, beans, okra, onions, radish, broccoli, and carrots. Stay away from celery, cabbage, and parsley.
Cabbage, turnip, cauliflower, and turnip are good. Add garlic for better pest suppression.
There are so many resources for this on the internet. Frankly, it also pays to experiment if you can because no source is 100% fool-proof when it comes to combining plants. Here are some additional resources:
Our good friend Wikipedia’s take on companion planting
Can’t leave out the Farmer’s Almanac
Happy companion planting! If you have tips of your own, leave comments below.