The Ultimate Guide to Effective Companion Planting 

December 20, 2023

Working with nature is far easier than trying to work against it. When you are developing your landscape plan, Companion Planting is an excellent way to get the best for and from all your plants. When you place plants that can work together near each other, you can have fewer pest problems, healthier plants, and a garden that is much easier to maintain. Both vegetable and flower gardens can benefit from companion planting when done effectively.

What is Companion Planting?

When two or more plants are grown near each other for the benefit of one or both, they are considered to be companion plants. Many companion plantings grow naturally in the wild, as certain plants thrive when they are near each other, and by observing this, gardeners and landscapers have adapted these strategies to make their gardens at home thrive. Companion planting provides a natural balance that is easy to maintain because the plants work together, not against each other. When you incorporate companion planting into your landscape design, you can use space more efficiently and effectively.

Why is Companion Planting Effective?

There are many benefits to companion planting. Plants with the same requirements for sun, soil type, moisture, and nutrients will often naturally grow together, creating a relationship that is efficient and beneficial for all. Many master gardeners have learned about the most effective companion plantings simply by observing how plants behave in nature. When plants thrive together in the wild, they will likely do well together in a cultivated garden. Fighting against nature is one of the most frustrating things an amateur gardener or landscaper will do, so leaning into the natural order of things will make for a happier landscaping experience.

In addition, there are other benefits to companion planting. Some of these include:

• Suppressing Weeds: sprawling plants planted among tall, upright plants is an efficient way to minimize space for weeds to take hold. Certain companionable ‘cover crops’ can choke out unwanted vegetation and add another ‘layer’ to a garden.
• Improved Plant Health: plants can change the chemistry of soil. When certain plants grow together, the soil is often beneficial to both plants, causing both to thrive. Plants with deep roots can bring nutrients to the topsoil, benefiting shallow rooting plants, and vice versa.
• Shade Provision: Tall, sun-loving  plants will get the sun they need while providing shade for shorter shade-loving companion plants.
• Support: Climbing plants will often use tall stems as support. Tougher plants can also take the brunt of severe weather and protect more delicate plants underneath.
• Pest Deterrence: Certain plants will repel insects and other predators, driving them away from plants that certain pests may be particularly attracted to.
• Improved Pollination: Plants that attract pollinators will often improve the health of surrounding plants, as well as the pollinators themselves.

What are Some of the Best Companion Plantings for Vegetables?

Many vegetables bring out the best in each other. Garlic is a natural repellent to many pests, especially deer and aphids. Growing garlic in a vegetable garden is one of the best ways to ensure that your vegetables make it through the growing season with far less harm from pests.

Basil can disorient predatory insects such as hornworms from Tomato plants (and the fragrant Basil will enhance the smell and taste of the ripe tomatoes for people too!) Maize, climbing beans, and winter squash are known as the “three sisters”; growing these Companion plants together dates back thousands of years, and these “sisters” still allow each other to thrive in todays’ gardens. Corn can also be used to shade lettuce and provide support for climbing beans and peas. Sprawling crops such as potatoes, squash, and cucumbers will deter weed growth within a large garden.

Companion plants are crops that help deter specific pests for each, and who won’t compete so much for space, water, or nutrients. Many plants have both their favorite companion plants, and their worst.

Today one can easily look online for the many successful “combo” plantings, as well as for which plants to not plant together, and for what reasons.

What are Some of the Best Companion Plantings for Flowers?

Variety in flower gardens can create some of the most beautiful landscapes and are inviting to valuable pollinators, particularly when you pay attention to which flowers work best as companion plants. In flower gardens, companion planting is quite beneficial for pest control. Herbs, particularly fragrant and flowering herbs, are often planted within flower beds to help repel pests.

For example, Rosemary, as a strong smelling and attractive herb, will repel snails. Snails like to feed on dahlias and can quickly decimate dahlia leaves and flowers. Planting Rosemary alongside dahlias can lower snail populations so your Dahlias can thrive.

Similarly, Yarrow is a flowering perennial herb that will also repel slugs and snails. When yarrow is planted among Larkspur, a beautiful tall flower, the snails, and slugs will avoid eating the larkspur during early growth, allowing it to grow to its full height. Catmint is a beautiful herb which is both a pollinator magnet and an aphid repellent. When planted among Calla-lilies, both plants will thrive, and the aphids will be deterred from infesting the Lilies.

Combinations of certain beautiful flowers not only deter pests, they also attract essential pollinators like birds, butterflies, and honeybees. Companion planting often works in multiple ways.

Lavender is a beautiful herb on its own, but it also attracts important pollinators, acts on suppressing weed growth, and repels several unwanted pests especially for Roses. Also, lavender will draw pollinators that are otherwise blind to the color of red Roses!

If you are beginning your gardening journey, it can be very beneficial to discuss your plans with a landscaping professional. Not only can these experts advise you on the best companion plantings, but they can also help you avoid designing your garden in a way where plants can harm each other. Once you have found the right plantings, the right landscape plan, and the right balance for your unique property and soil composition, your gardens will thrive, and you will reap the benefits for years to come.