How to grow Zinnia
Updated October 2026
Zinnias are easy, heat-loving annuals from Mexico that bloom from early summer until frost in almost every color, and they are among the best cut flowers and butterfly plants a home gardener can grow. Sow them directly after the last frost in full sun. Good air circulation and mildew-resistant varieties keep them looking good through humid summers.
📖 Our full guide: How to Grow Zinnia
Where to plant
Grow zinnias in full sun in moist, well-drained soil with plenty of organic matter; they are not picky about pH. Space them so air moves freely between plants, which helps prevent powdery mildew and leaf spots.
They bloom continuously from summer into fall in cooler summer climates and may slow down in the hottest weeks, picking up again as it cools.
- Florida: sow from February to April and again in August and September; South Florida can sow from late summer through winter.
- Gulf South and Texas: sow in March and April, and again in late summer in the Gulf South.
- Desert Southwest: sow in February and March, and again in September.
- California: sow from spring into midsummer.
- Mid-South, Mid-Atlantic and Southern Plains: sow from late April into early July; a midsummer sowing gives fresh plants for fall.
- Northeast, Midwest, Northern Plains, Mountain West and the Pacific Northwest: sow in late May or June after frost, or start indoors 4 weeks earlier.
- Hawaii: any month. Alaska: start indoors and plant out in June.
Choosing a variety
- Tall cut-flower types, such as Benary's Giant and California Giants, give long stems and big blooms.
- For low-maintenance, mildew-resistant bedding, choose narrowleaf zinnia (Zinnia angustifolia) cultivars such as the Crystal and Star series, or Profusion and Zahara hybrids. Profusion types produce new flowers above the old, so they need no deadheading.
- Pollinator-friendly single and semi-double flowers give bees and butterflies easier access than tightly double ones.
How to plant
- Sow seed directly where it is to grow after the last frost, about 1/4 inch deep, as zinnias grow quickly and dislike root disturbance.
- Keep the soil moist until seedlings appear, usually within a week in warm soil.
- Thin to 6 to 18 inches apart depending on the variety.
- For long cut stems, pinch the tip when young plants have three or four pairs of leaves to encourage branching.
Watering and feeding
Water deeply at the base when the soil starts to dry, and avoid wetting the leaves, which spreads mildew and leaf spots. Water in the morning.
Feed lightly at planting; too much nitrogen gives leaves at the expense of flowers.
Pruning and care through the year
- Deadhead or cut flowers regularly for continuous bloom.
- Remove mildewed lower leaves and keep plants spaced for air flow.
- Stake or net tall cut-flower varieties in windy spots.
Cutting flowers
Cut stems when the flower is fully open and the stem just below the bloom is firm; a stem that bends when wiggled (the wiggle test) is not ready and will wilt. Cut in the cool of the morning. Zinnias last about a week or more in a vase, and the more you cut, the more they bloom.
Growing in pots
Compact types such as Profusion and Zahara do well in pots at least 10 inches wide. Water regularly and give them full sun.
Propagation and saving seed
Zinnias are grown from seed. Seed from open-pollinated types can be saved from fully dried flower heads; hybrids will not come true.
Companion planting
Zinnias bring bees, butterflies and hoverflies into the vegetable garden, which helps pollination and pest control.
Good companions
- Tomato Draws pollinators and beneficial insects to the tomato bed.
- Bush Beans Brightens the bean rows and brings in bees.
- Cucumber Brings in the bees that cucumbers need for fruit set.
- Bell Pepper A warm-season partner that shares the same sun and season.
- Marigold Another easy summer annual for a pollinator border.
Pests and diseases
Powdery mildew and leaf spots are the most common problems, especially in humid weather. Japanese beetles love zinnia flowers in the East.
Pests to watch for
- Japanese beetle Metallic green and copper beetles chewing flowers and leaves in early summer, mainly in the East.
- Aphids Clusters on stems and flower buds.
- Spider mites Fine speckling and webbing on leaves in hot, dry weather.
Diseases to watch for
- Powdery mildew White powder on leaves, mostly in late summer; grow resistant varieties.
- Leaf spot Brown spots with paler centers (Alternaria) or small angular spots (bacterial leaf spot) in wet weather.
Common questions
When should I plant zinnias?
Sow them directly after the last frost once the soil is warm. In Florida and the South you can sow again in late summer for fall flowers. Choose your region at the top of the page for the months.
How do I stop powdery mildew on zinnias?
Grow resistant types such as Profusion, Zahara or narrowleaf zinnias, space plants for air flow, water at the base in the morning, and remove affected leaves.
When do I cut zinnias for the vase?
When the flower is fully open and the stem below it is firm. Wiggle the stem: if it bends, it is not ready. Cut in the morning.
Do I need to deadhead zinnias?
Most zinnias bloom more if you deadhead or cut them often. Profusion types grow new flowers over the old ones and need no deadheading.
Do zinnias attract butterflies?
Yes. Zinnias are one of the best annuals for butterflies, bees and hoverflies, especially single-flowered types.
Sources we checked: NC State Extension Plant Toolbox: Zinnia elegans; University of Illinois Extension: Zinnia.
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