Zinnia Companion Plants

Zinnias are hot-season annuals that provide months of color with just a few maintenance tasks such as deadheading and occasional fertilizing. Zinnias are sturdy and thrive in just about any garden situation with their bright colors and lovely deep green foliage. Grow them in large groups toward the middle or back of a cutting garden or pollinator garden. 

Growing zinnias is easy even for new gardeners. Choose a planting location with well-draining soil and full sun. These tender annuals need to be protected from late spring frosts and are best planted after nighttime temperatures are reliably over 50 degrees Fahrenheit. Fertilizing is only recommended for zinnias planted in very poor or sandy soil. Keep the soil evenly moist, and avoid over-watering, which can encourage root and foliage diseases. 

Shrubs To Plant With Zinnia

Zinnias can be incorporated into a mixed shrub and perennial border. Use them as replacements for early blooming perennials and as facer plants for taller growing shrubs with bare lower stems. Zinnias also look great mixed in with plantings of native shrubs like red twig dogwood, Rosa rugosa, and Deutzia. For bold color, try pairing Zinnias with Blue Star Juniper and Rose Glow Barberry, which grow easily together in full sun and poor soil.


Photo by K M, unmodified, Flickr, copyright CC BY 2.0 DEED

Perennials To Plant With Zinnia

Zinnias grow well with drought-tolerant perennials like yucca and ornamental grasses, providing a pop of long-lasting color. Use Zinnias to define the edges of more traditional perennial beds and fill in when other plants go dormant in the summer. Some of the best perennial companions include bearded iris, tall verbena, hardy salvia, and peonies, which all thrive in average soil and full sun like Zinnias. 

Annuals To Plant With Zinnias

Zinnias can be combined with other annuals for a long-blooming and low-maintenance garden display. Use Zinnias in bright colors to create a loud and vibrant display, full of energy, while the pastel shades are great to mix in with more sedate plants for a calming mood. 

To soften the hard edges of a planting bed or retaining wall, mix spiller plants like Dichondra and sweet potato vines with upright growing annuals like Zinnias. For added color and texture, include Marguerite daisies, pocketbook plants, cockscomb, and marigolds. Zinnias also work well in an annual cutting garden with cosmos, seed dahlias, and sunflowers. These plants not only provide flowers for arranging but also attract beneficial pollinators.


Photo by K M, unmodified, Flickr, copyright CC BY 2.0 DEED

Best Companion Plants For Zinnias in Containers

The compact growth of Zinnias makes them ideal for growing in containers and large planters as part of a seasonal display. Combine them with other hot-season annuals, such as Nasturtium, sweet alyssum, sweet potato vines, and Calibrachoa. These annuals can be used as spillers and fillers and have interesting leaf shapes. Their strongly colored flowers will bloom from early summer to the first frost in fall. 

Regular watering and fertilizing are crucial for the continued performance of annuals in containers. During periods of high heat or drought, containers may need daily watering. Fertilize mixed containers with a diluted liquid fertilizer every 2-3 weeks to promote more flower production and lush, vibrant foliage. 


Photo by K M, unmodified, Flickr, copyright CC BY 2.0 DEED

Plants Not To Grow With Zinnias

Zinnias will not grow well in soil that tends to stay boggy or is heavy with clay. These plants are susceptible to root rot, fungal rust, and powdery mildew outbreaks. To avoid the spread of these diseases, do not plant Zinnias near comfrey, squashes, cucumbers, and other members of the cucurbit family, which tend to get powdery mildew early in the growing season.

Zinnias also do not grow well in shade and may become leggy and weak without adequate sunshine. Avoid planting them with shade-loving plants like hostas, ferns, hellebores, lobelia, and impatiens. 

Best Plants To Grow With Zinnias

Grow Zinnias with plants that adore the sun and are not bothered by nutrient-poor or dry soil. Use Zinnias as part of pollinator plantings to encourage beneficial insects to visit a kitchen garden or naturalized location in your yard. These low-maintenance annuals can also add vibrant color to tropically themed designs utilizing dahlias, canna lilies, and coleus. 

Sources“Zinnias: The Hardest-Working Flower in the Summer Garden.” Chicago Botanic Garden. chicagobotanic.org