7 Plant Pairings That Naturally Keep Weeds Away—and Look Great Doing It

Weeds are a headache in any garden as they creep in between rows of veggies or twine their way through the leaves of annual or perennial flowers. But if you grow the right companion plants in your garden, you can naturally suppress weed growth and reduce the amount of weeding. Using companion plants to take up soil space is particularly beneficial for slow-growing plants that have a tough time competing with weeds.

Here are a few of the best ways to use companion plants for natural weed control, and clever ways to maximize your garden space and give you more room for your favorite flowers, veggies, and herbs.

1. Plant Herbs with Veggies

Fragrant herbs are often planted around vegetables to repel plant pests and attract pollinators to veggie flowers. The other benefit of growing herbs around the base of taller vegetable plants is that they fill up empty soil, so weeds are less likely to sprout.

There are lots of herb companion plant pairings to explore. For starters, try planting dill around your brassicas, basil beneath your nightshades, or low-growing Corsican mint or Roman chamomile around any plants that need insect pollination. Low-growing herbs such as creeping thyme and oregano work well in flower beds, too.

2. Pair Tall and Short Vegetables

While herbs make exceptional companion plants for many vegetables, pairing different types of vegetables also keeps weeds at bay. A classic example of this is the “Three Sisters," in which corn and beans are grown with winter squash so the squash leaves shelter the soil and prevent weeds from growing beneath the other crops.

Other combinations are radishes under taller veggies, or planting bush beans around crops that are heavy feeders, which reduces weeds and adds extra nitrogen to the soil. Use tall plants such as corn to cast shade over empty soil and keep weeds out.

3. Succession Plant Fast-Growing Crops

Weed seeds are quick to take advantage of any spot of open soil and often sprout in garden sections that are left bare after early-season crops have been harvested. To avoid this, consider planting fast-growing crops in succession. That way, no patch of your garden stays empty for long. Plants fast-growing crops like lettuce, spinach, arugula, and radishes. Start them from seed every few weeks in spots that are left bare after you’ve harvested early-producing crops from your garden. Some crops, such as spinach, do poorly in hot weather, so you might want to take a break during the summer, but others can be sown every few weeks from spring through fall.

4. Fill Space Between Rows with Low-Growing Plants

The empty soil in between rows of vegetables is a prime location for weed seeds to sprout. Some gardeners keep these areas covered with mulch or plastic to reduce weeds. Instead of mechanical weed barriers, use low-growing annual companion plants, like sweet alyssum or clover. Planted in between vegetable rows, they have a double benefit: They keep weeds down and attract beneficial insects to pollinate your crops and feed on plant pests.

5. Plant Low-Growing Flowers in Ornamental Beds

Although companion planting is most commonly used in vegetable gardens, companion plants also work in between perennial or annual flowers to keep weeds in check. Low-growing plants with dense growth habits or large leaves, such as hostas, are ideal for filling in space and shading the soil so weeds can’t grow. Groundcovers like creeping thyme, creeping phlox, wild ginger, and sweet woodruff can also add ornamental appeal to flower beds while blocking weeds with their mat-like growth habit.

6. Use Allelopathic Plants to Your Advantage

Some plants release compounds into the soil that make it harder for other plants to grow. Generally, this is not something you want to have happen in your garden; however, you may be able to use these allelopathic plants to your advantage if you're struggling with troublesome weeds. Plants like fennel, annual sunflowers, and buckwheat all have an allelopathic effect on certain types of weeds, but these plants also make it harder for garden plants to grow, so it’s important to plant them with care.

7.  Plant Cover Crops in Fall

Cover cropping and companion planting are two different gardening techniques that are both extremely helpful for reducing weeds. Typically, cover crop seeds are planted at the end of the growing season to keep weeds from intruding into gardens after the main crops are harvested. However, some cover crops can be grown as low-maintenance groundcovers in any season.

Clovers of all sorts are particularly useful as cover crops because they grow quickly, enrich the soil with their roots, and reduce weeds with their dense growth habit. Other cover crops like vetch, field peas, and daikon radishes are great choices too. Many cover crop plants are annuals, so you won’t need to worry about them becoming weedy later on.

More Tips for Controlling Weeds with Companion Planting

To get the most benefits out of weed-controlling companion plants, here are a few more important tips:

• Do your research. Make sure the plants you choose for companion planting will get along with each other and the other plants in your garden.
• Start early. Planting companion plants as early as possible in the growing season will prevent weeds from gaining a foothold in your garden.
• Follow plant spacing guidelines. When companion planting for weed control, grow plants slightly closer together than their spacing guidelines normally recommend, but not so close that your plants are overcrowded.
• Prune as needed. Throughout the season, be prepared to prune tall companion plants if they start to overshadow their neighbors. Pruning also encourages plants to branch out and produce denser growth that is better at blocking weeds.
• Combine with other weed control techniques. Although companion planting is an effective way to reduce weed problems, it works best when combined with other weed control strategies, such as mulching and no-till gardening.