Dahlias need heat and long days to hit their stride, so wait until April or May to plant — they'll repay your patience with months of cutting-garden color. Space them 18 inches apart in full sun and rich, well-draining soil, and stake the taller varieties early before they're loaded with blooms.

Each plant arrives ready to grow into a sturdy producer by midsummer. Pinch the top when it reaches a foot tall to encourage branching, and you'll have multiple stems for bouquets from July straight through until the first hard freeze.