Growing Dahlias in Zone 3B

Dahlias are showstopping flowers with endless variety in size, shape, and color. Worth every bit of effort.

Zone 3B has a short growing season — start seeds indoors when possible and use season-extending techniques like cold frames and row covers.

Top Growing Tips

• Plant tubers after last frost when soil reaches 60°F
• Pinch the center shoot for bushier plants and more flowers
• Stake tall varieties — dinner plate types get heavy
• Dig up tubers after first frost in zones 7 and colder; store in peat moss
• In zones 8+, tubers can overwinter in the ground with mulch

Companion Planting

Good companions: vegetables (attract pollinators), herbs

Avoid planting near: none in particular

Harvest Timeline

Flowering in 70-120 days from tuber planting; cut in the morning

About Zone 3B

USDA Hardiness Zone 3B has an average last spring frost around May 15 and first fall frost around Sep 15. All planting dates above are calculated from these frost dates. Your specific location may vary — check with your local extension office for the most accurate dates.