8 Dahlia Companion Plants That Guarantee Beautiful Blooms

Peach Giant Decorative Dahlia 'labyrinth' in flower — Credit: Alex Manders / Getty Images

Dahlias come in many shapes, sizes, and colors, filling the garden with show-stopping blooms from summer to fall. While dahlias are considered relatively easy to grow, one way to ensure they thrive and look their best is to grow them next to companion plants. Not only do companion plants help keep harmful pests at bay, but they also enhance the overall appearance of your garden. Ahead, we're sharing the flowers that experts say you should always grow next to dahlias if you want stunning, healthy blooms.

Carrie Spoonemore, co-creator of Park Seed's From Seed to Spoon app
Peggy Anne Montgomery, horticulturist representing Flowerbulb.eu
Linda Vater, plant expert on behalf of Southern Living® Plant Collection

01 of 08

Zinnias

orange king zinnia — Anton Nikitinskiy / Getty Images

Zinnias (Zinnia spp.) are wonderful companion plants for dahlias. "Their bright and cheery blooms attract beneficial insects like ladybugs and hoverflies while perfectly complementing the dahlias' vibrant colors," says Carrie Spoonemore, co-creator of Park Seed's From Seed to Spoon app. "Ladybugs and hoverflies help dahlias by controlling pests like aphids and mites, reducing the need for pesticides; plus, hoverflies also act as pollinators, supporting the plant’s blooming process."

Zones: 2 to 11
Size: 40 inches tall x 4 to 5 inches wide
Care requirements: Full sun; nutrient-rich, well-drained soil

02 of 08

Nasturtiums

Nasturtium flowers — Amit KUMAR / Getty Images

Nasturtiums (Tropaeolum) serve as trap crops for aphids, a common garden pest that feeds on plant sap. Growing nasturtiums next to dahlias will keep this insect at bay. "Their vibrant blooms also add a splash of color to the garden," says Spoonemore. "As a bonus, their leaves are edible and can offer a peppery addition to salads or other dishes."

Zones: 2 to 11
Size: 1 to 2 feet tall x 1 to 2 feet wide, depending on variety
Care requirements: Full sun; well-draining soil

03 of 08

Marigolds

Marigold 'Queen Sophia' - 1979 AAS Winner.
Photo Courtesy of the National Garden Bureau, Inc.

Marigolds (Tagetes spp.) have cheerful flowers that not only visually enhance your garden but also serve as a natural pest repellent, says Spoonemore. "They keep unwanted aphids and nematodes away while their bright blooms attract pollinators, ensuring a balanced, healthy, and thriving garden," she says.

Zones: 2 to 11
Size: 6 to 36 inches tall x 6 to 24 inches wide
Care requirements: Full sun; well-draining soil

04 of 08

Canna Lilies

Pair dahlias with a backdrop of canna lilies (Canna spp.) for a beautiful late summer and fall garden. "Dahlias can grow up to 5 feet or more, capturing attention with their vibrant blooms, but when set against the lush, dramatic foliage of cannas, they become the ultimate showstoppers," says Peggy Anne Montgomery, horticulturist representing Flowerbulb.eu. "This pairing enhances the dahlias’ vivid colors, adding depth and visual drama to your garden."

Growing zone: 9 to 11
Size: 3 to 5 feet tall x 2 to 4 feet wide
Care requirements: Full sun; moist, well-draining soil

05 of 08

Montbretia

Montbretia (Crocosmia) creates a color combination hummingbirds can't resist when planted in front of dahlias. "With its slender, arching stems and fiery blooms, crocosmia makes a perfect partner for the larger, more extravagant blooms of Dahlias," says Spoonemore. "Both come in stunning shades of red, orange, and yellow, giving you plenty of options to create a cohesive yet dramatic color palette."

Zones: 5 to 9
Size: 2 to 4 feet high x 1 foot wide
Care requirements: Full sun, moist, organically rich, well-draining soil

06 of 08

Camellias

Camellia pink flowers — Elizabeth Fernandez / Getty Images

Camellias (Camellia spp.) pair perfectly with dahlias. "Bloom time is the secret behind this perfect pair. "Just as dahlias’ blooming period begins to wind down in the fall, camellias burst forth with flowers, blooming into the colder months," says Linda Vater, plant expert on behalf of Southern Living® Plant Collection. "As dahlias’ foliage fades, camellias continue to provide structure to your cut flower garden or ornamental bed with their strong woody branches and evergreen foliage."

Zones: 7 to 9
Size: 7 to 12 feet tall x 5 to 10 feet wide
Care requirements: Partial to full sun; well-draining, slightly acidic soil

07 of 08

Gardenias

Dahlias are a beautiful addition to an ornamental or cut flower garden. "When paired with plants that play to the other senses, they can help craft a multi-sensory garden experience," says Vater, adding that fragrant gardenias (Gardenia jasminoides) are one such ideal pairing. Not only do they look visually beautiful together, but they also have similar care requirements, both thriving in similarly sunny settings with slightly acidic and well-drained soil.

Zones: 7 to 11
Size: Depends on variety
Care requirements: Partial sun; moist, well-draining soil

08 of 08

Sweet Alyssum

Sweet alyssum (Lobularia maritima) is a low-growing plant that will beautifully fill in the area around your dahlia flowers. Known for its dainty, cheerful blooms, this annual flower can cover an area in a short period of time. Keep in mind that it can be invasive in warmer climates, so it's best for cooler regions.