Planting “companion” plants near each other in the garden can benefit both the gardener and the plants. The plants will be happier, and there will be less work for the gardener. (I’m all for less work!)

Everybody find a buddy: “Companion plants” are ones that benefit each other. Some plants add nutrients to the soil that other plants can use, saving the gardener fertilizer. Some plants repel pests that could destroy other plants, saving the gardener pesticides. Some plants provide shelter or structure that is needed by other plants, saving the gardener the hassle of mulching, shading, and staking the plants.

Nutrients are added to the soil by plants such as peas, soybeans, and other legumes (and also alfalfa) because these plants fix nitrogen in the soil. Any crop, planted in the same spot as these plants have previously been planted, benefits from the extra nitrogen in the soil. Other plants aide the production of neighboring plants in different ways. Basil planted with tomatoes is said to improve the flavor. Marjoram and oregano can be planted throughout the vegetable garden to improve the production a variety of vegetables.

By repelling pests, some plants save their neighbors as well as themselves. Marigolds repel a host of insects, including nematodes (in the soil), beetles, and tomato worms, and are planted throughout the garden to protect many plants. Planting garlic and parsley near a gardener’s prize roses can protect them. Parsley also deters pests that would otherwise feed on a gardener’s prize tomatoes. Chives and Nasturtiums repel bugs and are grown around the bases of fruit trees to protect them. Radishes can be planted with squash to deter squash borers. Many herbs work against specific pests, and should be planted with the vegetables that these pests bother. Thyme repels cabbage worms. Basil repels thrips. Sage repels the cabbage moth and the carrot fly. And Rosemary deters cabbage moths, carrot flies, and bean beetles.

Many plants help their neighboring plants by nature of their structure. Some, like thyme and radishes, can provide a living mulch that smothers weeds. Others, like alfalfa and caraway, loosen the soil, making it easier for other plant roots to break through it and go deeper in search of water and nutrients. This can save the gardener hours of backbreaking hoeing. Other plants, like sunflowers and Jerusalem artichokes, can provide shade for other crops, or can act as a living trellis for vining crops like beans.

Some combinations of plants provide multiple benefits. For instance, beet and onions can be planted together to help each other. The onions repel insects that might harm the beets, and the beets add minerals to the soil that the onions can use to grow better. The traditional Native American combination of corn, beans, and squash, called the “Three Sisters,” provides different benefits for each of the three plants. Corn provides support for the beans to grow and shade for the squash. In return, the beans add nutrition into the soil for the corn and squash to use. The squash smother the weeds around the corn and beans, acting as a living mulch for them.

In all these examples, a gardener reduces the amount of work in the garden simply by placing plants near others that they help or that help them. With a little planning beforehand, a gardener can save themselves time and money. The simple act of using “companion plants” can supplement or replace gardening tasks such as fertilizing, applying pesticides, hoeing, mulching, shading, and staking plants.