Companion Planting

What is Companion Planting?

Just as humans often benefit from a little companionship, so do plants. However, like humans, the proper plants must be placed together for these benefits to occur. After all, not everyone nor everything can be friends.

Companion planting is the act of arranging crops so plants that benefit one another are next to each other.

Why Use Companion Planting?

Companion planting provides a number of benefits including:

• keeping away pests,
• attracting beneficial insects,
• bringing in pollinators, and
• improving soil quality.

By using companion planting, you’ll notice an increase in your plants’ health. Also, you might be able to cut back on the time and cost associated with pest control, fertilization, and irrigation.

Deter Pests

Unfortunately, some type of insect is interested in eating just about every crop you grow. Rather than waiting until pests attack your plants and then treating with pesticides, try using companion planting to deter pests.

Just as many insects only attack a certain crop family, pests are also repelled by certain plants. For example, carrot flies attack carrots. However, these flies don’t like members of the allium family such as onions and leeks. By planting onions next to carrots, you repel these flies from your carrots.

It’s not magic, it’s ecology.

Some plants that are great at deterring pests include marigold and nasturtiums. Both of these flowering crops help keep away common pests including aphids, bean beetles, and potato beetles. As a bonus, they both provide cheerful, edible blooms.

Attract Beneficial Insects

Another way companion planting helps control pests is by drawing in beneficial insects. Some common types of these helpful insects include ladybugs, lacewings, and assassin bugs.

Oftentimes, only one stage of a pest attacks an insect. However, other life stages still need a place to live!

For example, braconid parasitic wasps lay their eggs in the bodies of live insect pests such as tomato hornworms. When the eggs hatch, the larvae feed on the insect host’s body. Eventually, the larvae eat their way out of the host, form a pupa on the host’s body, and turn into adults. If you haven’t already figured it out, this process kills the host.

However, the adult wasps do not feed on insects. Rather, they eat nectar. Therefore, including plants such as yarrow and dill provides adults with food. When adults have a food source, they are more likely to stay around and continue parasitizing your pests.

Attract Pollinators

In case you don’t know, lots of plants rely on animals for pollination. Some common pollinators include bees, flies, and birds.

You can attract these pollinators to your garden by providing them with food sources. Even if you’re hoping bees visit and pollinate your cucumber plants, you should still supply these pollinators with other sources of food. Try planting flowers such as echinacea, yarrow, and marigold to provide sources of pollen and nectar.

Companion planting can also provide additional habitat for pollinators. Planting tall, voluminous plants such as tomatoes and peppers can give these pollinators a place to hide from predators.

Improve Soil Quality

Due to their unique growth habits and biology, plants have various effects on the soil.

While all plants improve soil structure through their root growth, some crops do this better than others. Crops with deep roots, such as carrots and daikon radishes, can help break up compacted soils. This improves soil drainage and aeration for the following crops.

Legumes are another crop that enhances soil quality. Crops including peas, beans, and clover have special root nodules that turn nitrogen from the atmosphere into a plant-available form. Therefore, these plants act as a natural fertilizer for surrounding crops.

Improve Plant Habitat

By utilizing the physical properties of plants, you can improve your plants’ growing environment.

For example, some crops such as beets and lettuce, benefit from some shade in the summer. By planting these crops next to tall crops such as tomatoes, you provide natural shade.

Another example is planting corn and pole beans together. The corn acts as a trellis for the pole beans, while the beans provide the corn with nitrogen.

Companion Planting Chart for Vegetables

To be considered good companion plants, vegetables must provide at least one of the benefits listed above.

Just as some plants make great companions, some plants harm each other. For example, onions slow the growth of beans and peas.

When you’re planning out your garden, consider this companion planting chart.

Herb Companion Planting Chart

Just as some vegetables are friends and some are enemies, herbs can either help or harm their neighboring plants.

Herbs often contain aromatic compounds, which might be why you want to include them in your garden and kitchen. However, before you plant herbs, don’t forget to think about how these compounds affect other plants. If you’re looking for ways to use herbs in companion planting, here are some examples.

Basil and tomatoes are a great combo not only on your plate but also in the field. The compounds basil produces help deter pests including aphids and spider mites.

Nasturtiums help repel two of the most common pests of squash and cucumber: the squash bug and cucumber beetle.

Borage is an all-around excellent companion plant. If you look at a companion planting chart, you’ll see it’s a friend to almost all plants. This is because it deters a number of common pests, including hornworms and cabbageworms.

Planting Together

Now that you know about companion planting and how it benefits your plants, it’s time to get to work. Grab a companion planting chart and start planning your garden.

Companion Planting Chart