Planting and Growing Zinnia Flowers

What Are Zinnias?

Zinnias open non-stop flowers, from spring through fall, that are big, beautiful and colorful. Zinnias are an annual plant, which means they last just one growing season in the garden. But since they’re a snap to grow from seed, it’s easy to plant some each year. They’re carefree plants, thriving with sun, heat and drought.

Many different types of zinnias exist: tall varieties with long stems perfect for snipping and sticking into vases, or mounding types ideal for edging planting beds or filling containers. This undemanding annual is great for beginning gardeners.

Zinnia Basics

Botanical Name: Zinnia spp.
Common Name: Zinnia
Bloom Time: Summer to frost
USDA Hardiness Zones: Grown as an annual in all regions

Zinnia FAQs

Are zinnias easy to grow? Zinnias are low-maintenance plants that are so easy to grow they're often recommended for children to plant.

Are zinnias perennial flowers? No, zinnias are annual plants that you need to plant each year.

Can you grow zinnias in pots? Zinnias adapt readily to pots. Shorter varieties and newer ones, like Zahara and Profusion, fill a container with continuous blooms all season.

How tall do zinnias grow? It varies by type. Cutting zinnias often grow 1 to 3 feet tall, while smaller mounding types grow 12 to 18 inches tall.

When should I plant zinnias? Wait for warm weather, when night temperatures stay reliably above 50° F.

Do zinnias need sun? Zinnias flower best in full sun, but still stage a pretty show in part shade.

Do deer eat zinnias? Deer typically ignore zinnias, as do rabbits. Zinnias are generally pest-free.

Can I save zinnia seeds? You can save seeds from open-pollinated types, but not from hybrids. This information should be on the seed package, or you can look it up online. Let flowers dry on the stem, then clip them and gently crush them in your hand to release the seeds.

How to Grow Zinnia from Seed

Zinnia grows easily from seed sown directly into garden soil. Tuck zinnia seeds into soil when night temperatures stay reliably above 50° F. Follow directions on the seed packet about how deep to plant the easy-to-handle seeds. Some gardeners start zinnias indoors 4 weeks before frost to yield an early crop of blooms.

Light

Plant zinnias in a spot with full sun, except in the hottest regions of the country. In these areas, zinnia plants thrive with light shade during the afternoon.

When to Plant Zinnia

Wait until all danger of frost has passed before sowing zinnia seeds. These flowers are native to Mexico and can’t stand a chill. Typically when you see zinnia plants for sale at garden centers in spring, it's okay to tuck those into planting beds or pots, as long as there's no frost in the forecast.

Soil

All this bloomer needs to survive is well-drained soil with consistent moisture. If your soil is heavy clay, work organic matter into planting areas prior to planting.

Location

Read plant tags carefully to make sure you’re buying the right zinnia for the use you have in mind.

Tall cutting-type zinnias do best in planting beds. Cut and Come again zinnia (Zinnia pumila) grows to three feet tall and flowers best in planting beds.

Look for smaller zinnias developed for use in pots, window boxes or even hanging baskets. Narrowleaf zinnias (Zinnia angustifolia) make a terrific edging in pots or planting beds.

Fertilizer

It’s also a good idea to add slow release fertilizer to planting beds. Work it in at the recommended rates on the package. Or improve soil by adding compost or composted manure.

Caring for Zinnia Flowers

Water

Once established, plants are fairly drought tolerant. Avoid overhead watering unless you can water plants early in the day. Soaker hoses or drip irrigation provide good watering options. Zinnias are prone to several fungal diseases that attack leaves. These diseases tend to develop more quickly when leaves stay wet overnight.

Having adequate air circulation also helps reduce disease. Plant zinnias according to recommended plant spacing on pot tags — don’t crowd plants.

Deadheading

With most zinnias, removing spent blooms encourages more flower buds to form. Some of the newer types, like Profusion, are self-cleaning and don’t need deadheading. Check plant tags to learn if your zinnia is self-cleaning.

Zinnia Varieties and Uses

Zinnia is an old-fashioned favorite with plenty of new offerings. Plant breeders have developed zinnias that capture the classic beauty in low-maintenance packages.

‘Oklahoma’ Zinnia

Many flower farmers say that ‘Oklahoma’ zinnia is the only zinnia you need to grow. This heirloom bloomer has been raised for at least 75 years and has a record of dependability in the garden. Plants show better mildew resistance than other Zinnia elegans varieties, and the 2-inch-wide flowers are consistently double and fluffy. Expect to get many blooms from one plant, which grows 30 to 40 inches tall and 12 to 18 inches wide.

Zinnia 'Queen Red Lime'

‘Queen Red Lime’ zinnia (Zinnia elegans) unfurls a bloom that’s stunning and elegant. Petals showcase rings of hues—faded red, dusty raspberry, lime green—surrounding a ruby red center. Sturdy plants grow 30 to 40 inches tall and yield many stems for cutting or leaving in place to beckon butterflies. Flowers are mostly double and semi-double with a few singles. When looking to buy this or other unusual colors of ‘Queen’ zinnia, you may also see them labelled as ‘Queenie' or 'Queeny.'

‘Aztec Sunset’ Mexican Zinnia

‘Aztec Sunset’ Mexican zinnia (Zinnia haageana) explodes with floral fireworks in shades of gold, burgundy, pink, orange, red and white. Narrow leaves help this zinnia survive drought, heat and humidity, as indicated by the Dallas Arboretum’s Flameproof Plant designation. Mexican zinnia grows 15 to 24 inches tall and up to 12 inches wide. Remove faded double blooms to keep the flower show going strong.

Profusion Zinnia

Profusion zinnia’s name is accurate, since each plant is covered with a profusion of flowers. Profusion (Zinnia grandiflora) opens 2-inch-wide flowers on plants that tolerate heat, cold and high humidity—all without missing a blooming beat. Look for blossoms in a range of colors, including white, gold, pink, orange and bicolors. This is a shorter zinnia, growing 10 to 12 inches tall and 12 to 15 inches wide. It’s a perfect choice for edging planting beds or filling containers.

Zinnia Zahara

Zahara zinnias (Zinnia marylandica) deliver season-long color with 3-inch blossoms in saturated hues, like this Double Zahara Fire. Other bloom colors include pink, white, gold and bicolors. Plants are bushy, growing 12 to 18 inches tall and wide. Zahara is similar to Profusion, but with bigger plants and bigger flowers. You don’t have to remove spent flowers on Zahara; this prolific bloomer is self-cleaning. Plants are heat- and drought-tolerant, and deer and rabbits ignore them.

Cactus Flowered Mix Zinnia

Cactus Flowered Mix is an heirloom zinnia (Zinnia elegans) that created a splash when it debuted in the 1920s. Quilled and curled petals give the 5-inch blooms a distinct look. Flowers are single or double and come in a rainbow of hues: red, white, yellow, pink and orange. Easily grown from seed, cactus-flowered zinnias make a perfect addition to garden-fresh bouquets. Plants grow 30 inches tall and 12 to 18 inches wide.

'Starbright Mix' Creeping Zinnia

‘Starbright Mix’ creeping zinnia (Zinnia angustifolia) is a low-growing type that works beautifully in planting beds as an edging. It also fills a container to overflowing. Also known as Mexican or narrowleaf zinnia, this is a heat- and drought-tolerant annual with 2-inch single flowers in shades of gold, orange and white. Plants have strong disease resistance and grow 12 to 15 inches high and 8 to 12 inches wide.

Crestar Zinnia

Crestar Mix zinnia is an All-America Selections Winner, which means it performs well in many different growing zones. A type of crested or scabiosa-flowered zinnia, this bloomer opens semi-double 3- to 4-inch-wide flowers with a pronounced central disc. Blossom colors showcase a vibrant palette, including peach, yellow, white, pink and red. Plants grow well in summer heat and humidity, reaching 18 to 23 inches tall and 10 inches wide.

'Dreamland Mix' Zinnia

‘Dreamland Mix’ zinnia (Zinnia elegans) is a classic variety that’s often sold in cell packs. Fully double blooms are petal-packed and unfurl in the classic bright zinnia hues of yellow, pink, red, orange and white. Flowers open to 4 inches across, making a strong show in a planting bed, container or vase. Plants grow 12 to 14 inches tall and wide and feature heat and drought tolerance.

'Zowie' Zinnia

‘Zowie! Yellow Flame’ zinnia is a mouthful, but one look at those bicolor blooms and you’ll be calling it ‘Zowie!’ for short. The red and yellow flowers open 3 to 4 inches across on sturdy stems ideal for cutting. Plant researchers tested these blossoms for vaselife, which comes in at two weeks. A type of Zinnia elegans, ‘Zowie!’ stands up to heat and earns its keep easily in planting beds or pots. Plants grow 24 inches tall and wide.