Light. Plant in full sun for the most flowers and the fullest growth.
Water. Water regularly while it settles in. It is somewhat drought tolerant but flowers better with regular watering.
Soil and feeding. It adapts to most soils as long as they drain well.
Size. Usually 3–5 ft tall and 6 ft or more wide, with arching, rush-like stems. Give it room to sprawl; stems that touch the soil can root.
Problems to watch. It is relatively pest free, with no serious insect or disease problems.
Good to know. Butterflies and hummingbirds visit the flowers. It is moderately salt tolerant. It is tender to cold, so cover it when a freeze is forecast.
Sources: UF/IFAS Gardening Solutions: Firecracker Plant · NC State Extension Plant Toolbox: Russelia equisetiformis
