How to Grow Dahlia

Updated June 2026

A warm-season flower for the home garden across the warmer US.

What it looks like as it grows

Dahlia is a rewarding warm-season crop for backyard growers.

When to plant

Plant Dahlia in spring once the soil has warmed and all frost has passed. In the warmest regions a second crop is possible in late summer. See your region on the dahlia page for exact timing.

Varieties

Dinnerplate Mix, Huge cut-flower blooms (garden centers (tubers))

How to grow it

Sun & soil: full sun, rich well-drained soil with even moisture.
Spacing: about 24 in between plants.
Sowing: sow about 4 in deep.
Water: roughly 1.6 gal per plant every 2 days in hot weather.

Pests & problems

Watch for Aphids, Slugs, Snails and Earwigs. In humid regions, Powdery mildew, Botrytis and Dahlia mosaic virus can appear, so space for airflow and water at the roots in the morning.

Harvest

Dahlia is usually ready to harvest in about 3 months. Pick regularly to keep plants productive.

When to plant in your region

Pick your region to see exactly when to plant dahlia where you garden.

See what to plant this month

Pick your region for a month-by-month calendar tuned to your climate.

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