10 Plants You Should Always Grow Next to Zinnias, According to Gardening Experts

Marigolds

Marigolds and zinnias share many wonderful qualities, making them excellent garden companions.

“They both attract pollinators and beneficial insects,” says Linda Langelo, horticulture specialist at Colorado State University. "The scent of marigolds helps repel thrips, beetles, and aphids.”

• Zones: Annual in all zones
• Mature size: 6 to 24 inches tall
• Care requirements: Full sun; moderate water; well-drained soil

Cosmos

“We use companion plants in all of our fields,” says Leslie McCardell, owner of Hopewell Flower Farm. So if you're looking to amplify the pollinator power of your zinnia patch, she says cosmos are a must.

These daisy-like flowers bloom for months, often right alongside zinnias, and thrive in the same hot, sunny conditions.

• Zones: Annual in all zones
• Mature size: 1 to 4 feet tall
• Care requirements: Full sun; well-drained soil; minimal watering once established

Nasturtiums

Nasturtiums aren’t just known for their looks—they're also hardworking companions for zinnias. These vibrant annuals are considered classic trap crops, attracting aphids away from zinnias, while also masking the flowers’ scent from pests.

• Zones: Annual in all zones
• Mature size: 12 to 18 inches tall; 1 to 3 feet spread
• Care requirements: Full sun to partial shade; well-drained soil

Black-Eyed Susans

With their golden petals and dark central cones, black-eyed Susans bring bold color and a wildflower feel to the garden.

“[They're] also a good companion to zinnias,” says Langelo. “They both thrive in full sun, are tolerant of dry soils, and attract beneficial pollinators, such as butterflies and bees."

• Zone: 3 to 9
• Mature size: 2 to 3 feet tall x 2 to 3 feet wide
• Care requirements: Full sun; moist, organically rich soils

Echinacea

According to McCardell, echinacea, also known as coneflower, shares similar appeal to pollinators. Additionally, both echinacea and zinnias thrive in full sun, tolerate dry spells, and offer a long season of blooms that attract bees and butterflies.

• Zones: 3 to 8
• Mature size: 2 to 5 feet tall x 1 to 2 feet wide
• Care requirements: Partial shade to full sun

Swiss Chard

Langelo says that Swiss chard and other leafy greens make great companions for zinnias. Early in the season, they serve as a ground cover to help zinnias establish themselves. Later, the zinnias provide shade that helps keep the soil moist.

• Zones: 2 to 11
• Size: 12 to 24 inches tall x 9 to 18 inches wide
• Care requirements: Full sun; fertile, well-drained soil

Basil

Basil helps deter certain insect pests that might otherwise be attracted to zinnias, according to Bill Hageman, owner of Peaceful Valley Farm & Garden Supply. Plus, the leafy herb thrives under similar conditions.

• Zones: 3 to 11
• Mature size: 6to 8 inches tall
• Care requirements: Full to partial sun; rich, well-drained soil

Tomatoes

Zinnias and tomatoes make excellent neighbors. “The tall blooms of zinnias help support pollinator activity, which in turn promotes flowering and growth in other plants in the garden,” Hageman says. 

According to Hageman, zinnias are also commonly used as a trap crop, luring aphids and beetles away from tomatoes.

• Zones: 3 to 11
• Mature size: 3 to 5 feet tall, 2 to 4 feet spread
• Care requirements: Full sun; loamy, well-drained soil

Beans

Beans serve a dual purpose when planted near zinnias. “Green beans or any legume fix nitrogen in the soil. This provides healthy growth for the zinnias,” Langelo says. “In turn, zinnias attract pollinators for the beans.”

• Zones: 2 to 11
• Size: 2 to 3 feet wide x 2 to 15 feet tall
• Care requirements: Full sun; well-drained soil

Squash

Samantha Rothman, owner of Fairview Farm and Flowers, loves growing zinnias with her squash plants.

“We find that, aesthetically, they break up the monotony of the large, green squash leaves with their array of colors,” she says. “Plus, the plant’s linear shape and height allow it to grow near the squash without competing for the same growing space.”  

What’s more, the pollinators that come for the zinnias will also help increase squash crop yields.

• Zones: 3–10
• Mature size: 12 to 24 inches tall x 24 to 36 inches wide
• Care requirements: Full sun; rich, well-drained soil; ample water