Dahlias deliver unmatched drama in colours that defy description. Grow them from tuber to trophy bloom with this complete care guide covering planting, feeding, pinching, and overwintering.
Choosing Your Tubers
Start with firm, plump tubers from a reputable nursery. Avoid anything soft, shrivelled, or showing mould. For first-time growers, ball dahlias and semi-cactus types tend to be most forgiving, while dinner-plate varieties reward extra attention with spectacular results.
When and How to Plant
In Memphis and other Zone 7b gardens, plant tubers outdoors after your last frost date, typically mid-April. Choose a spot receiving at least six hours of direct sun. Set tubers 4-6 inches deep with the eye facing upward, spaced 18-24 inches apart.
Feeding for Maximum Blooms
Dahlias are hungry feeders. Begin a low-nitrogen, high-phosphorus fertiliser programme once plants reach 12 inches. A monthly feed of bone meal and a weekly liquid kelp drench gives outstanding results.
Pinching and Disbudding
For bushier plants and more blooms, pinch out the central growing tip when plants reach 12 inches. For exhibition-quality blooms on larger varieties, disbud by removing the two smaller buds flanking each terminal bud.
Overwintering Your Investment
After the first hard frost, cut stems to 4 inches and carefully dig the clumps. Cure them upside-down in a dry location for a week, then pack in barely moist vermiculite and store at 40-50 degrees Fahrenheit.
💡 Pro Tip: Deadhead spent blooms every 2-3 days during peak season. Dahlias bloom more prolifically the more you cut - so fill every vase in the house!
