Plant in well-drained soil with full sun exposure. Space plants about 18-24 inches apart. Water regularly, keeping the soil consistently moist but not waterlogged. Fertilize with a balanced, slow-release fertilizer in early spring. Deadhead spent blooms to encourage continuous flowering. Divide clumps every 3-4 years in early spring to maintain vigor. Protect from extreme heat and provide good air circulation to prevent mildew.