Top 4 Benefits of Companion Planting in the Garden

Shelter from Weather Stress

An important benefit of companion planting is the use of plants to shelter others from weather stress. The structure of each plant must be considered along with their individual needs. Weather stressors for plants can include intense sun, high winds, and heavy rain. A low growing vegetable that likes filtered light can be positioned on the shady side of a taller plant, such as a sunflower or corn stalk.

Seedlings are often structurally weak, as they are still developing, making them susceptible to damage from wind. “Nurse crops,” typically used for erosion control and weed prevention, can also offer protection from wind if they are larger and faster growing than the seedlings. Plants with dense foliage, such as sweet potato vines, and/or large leaves, like kale or cabbage, help disperse the waters from heavy rain and reduce damage to smaller plants. Similarly, the water dispersion from these wide, umbrella-like, leaves can deter soil erosion.

Planting Beefsteak Tomatoes and Celery

Here I was planting a celery stump I had rooted in water. The large tomato vine it was planted under helps to filter the light and lessen its intensity. The celery plant prefers moist soil, in a cool area where it gets a break from afternoon sun. This large tomato plant will take the brunt of the afternoon sun and leave dappled sunlight for its companion beneath.

Soil Enrichment

Some plants improve the soil by pulling elements, such as nitrogen, from the air and storing it in their root system within the soil. This has a balancing effect as many plants are heavy nitrogen feeders. Plants need a balance of nitrogen, potassium, and phosphorus for building healthy plant cells.

If the soil has been depleted of the much-needed nitrogen, a “nitrogen fixer” would be an excellent solution. Legumes are a well-known nitrogen-fixer. An ideal companion for a legume would be one that feeds heavily on nitrogen, such as corn.

Another way companion plants can enrich the soil is by producing natural substances that reduce bacteria, fungus, and harmful insect populations in the soil. Marigolds are a good example of this as they produce a natural nematode repellent. They do well when paired with plants that are susceptible to nematodes, such as tomatoes, potatoes, and peppers.

Marigolds

I like using marigolds as a companion plant within my veggie patch. Aside from the soil amending properties for pest control, they also have a cheerful look. We have a lot of deer around our property, so we always have to be mindful of plantings. Luckily, the deer and rabbits don’t like marigolds and seem to steer clear of beds with them in it. Lastly, as you may have seen in our post Homemade Immunity Tea, we like to use the flowers in a tea blend at the end of the season.

Pest Control

On that note, let’s talk more about pest control. We know about the uses of marigold for pest control within the soil but how about above the soil? There are so many flying insects that damage crops. What can be done about them?

Predator bugs. We can plant companions that will attract just the right predator bugs to keep the pest populations manageable. Lady bugs are a good predator bug for controlling aphid populations. One way to attract them is by planting sunflowers near the plant you wish to protect.

Aphids colonize on a plant, feeding heavily, depleting its nutrient reserves, and secreting a sticky residue, called honeydew. The honeydew attracts sooty mold. What a mess! I have had these little buggers destroy a beautiful hibiscus tree before I knew what they were and how to get rid of them. Wish I knew then that I could have planted some ladybug friendly plants to clean up the mess for me.

Some small insects blow around in the wind and land wherever they land, causing destruction to whatever is unlucky enough to be their landing site. In this case, you can shield a more valuable crop from these insects by planting taller filtering plants, like dill or cilantro. Their height and web-like foliage will capture the bugs, keeping them away from those you wish to protect.

Another form of pest control is to plant companions from the allium family, ex: garlic, onions etc., that release a pungent scent. Many pest insects find this scent to be undesirable and will look for an easier, more pleasant smelling, target.

Cherry Tomatoes and Onion

With the above in mind, I wanted to protect my cherry tomato plants from whiteflies, a common tomato-loving pest. Alliums are a good companion for deterring whiteflies and protecting those juicy little tomatoes for us to enjoy later! I had some onions growing in other parts of the yard. Since, I have found that they transplant easily, I scooped some up and moved them next to my cherry tomato vines.

Weed Control

The use of companion planting for weed control is a simple concept. Companion planting involves grouping beneficial plants close together. When plants are within close proximity, it really doesn’t leave much room for weeds to grow.

Some veggies are spaced further apart in the garden rows. Cabbage, for example, needs a bit more room to grow. As a seedling it is small leaving a lot of bare soil around it. Left alone, this is prime weed territory. If you plant a fast-growing placeholder crop between your rows of cabbage the weeds will be greatly reduced.

Cilantro, mustard, spinach, and lettuce grow quickly, filling in spaces. As the cabbage grows and requires more room, you harvest the fast growers, and enjoy them while you wait.

Red Noodle Pole Beans

Notice in the picture below I have a dense bush of pole beans that have filled in the area around my sugar cane plant. The sugar cane is still young and small but it will grow to be 12+ feet high.

This variety of bean likes to grow up a pole. The sugarcane stalks will act as a trellis for the vining bean plant. In the meantime, the dense foliage suppresses weed growth in the surrounding bed.