How to Grow Dahlias: Late-Season Color & Cut Flowers

Dahlias bloom from midsummer to frost in sizes from bedding plants to 3-ft giants with dinner-plate blooms. Easy with a few rules, they fill the late-season color gap beautifully.

Growing Basics

• Plant tubers in spring after soil warms (when tomatoes go out).
• Choose firm, sprouting tubers from quality sources.
• Rich, well-drained soil; crown just below surface. Don't water until sprouts appear.
• Stake tall/dinner-plate varieties at planting (tomato cages work).
• Fertilize biweekly with low-nitrogen bloom booster.
• Water consistently; avoid late-evening watering to prevent powdery mildew.
• Pinch at 6–8 in. (above 3rd leaf set) for bushiness; deadhead weekly.
• Hardy to zone 7; usually grown as annuals.
• Overwinter tubers: lift pre-frost, cut to 6 in., dry, store in sawdust/vermiculite in freeze-free area.
• Cut flowers early morning; BHG hot-water treatment (2–3 in. very hot water, 1 hr) extends vase life to 4–6 days.

Favorite Varieties (from Swan Island Dahlias)

• Dreamcatcher – 4 ft, 6-in. blooms, garden focal point.
• Tahiti Sunrise – 2.5 ft, 5-in. spiky blooms.
• Bonne Esperance – 12 in., single pink, heirloom from 1940s, early/long bloom.
• Emory Paul – 4.5 ft, 10+in. dinner-plate, exhibition quality.
• Bridezilla – 5+ ft, 6-in. white with yellow eye, stunning cut flower.

Order a few for your own garden—share your dahlia experiences in comments!