When to Plant Ageratum Seeds

Plant outdoors directly after the last frost of the season, or start indoors 8-10 weeks before last frost.

Where to Plant Ageratum Seeds

Plant in full sun where available (6-8 hours of sun per day). Ageratum will tolerate partial shade (4-6 hours of sun per day), and prefers prefers partial shade in exceptionally hot environments. Plant in moist, average, well draining soils. Ageratum is prone to wilt if left dry, and may die outright if left dry for too long in a hot environment.

How to Plant Ageratum Seeds

Ageratum seeds require light to germinate, so be careful not to cover them when planting. Learn more about germination light requirements here.

Lightly press 4-8 seeds into the surface of the soil no deeper than 1/8th of an inch. Seeds should not be buried, as exposing seeds to sunlight is needed for germination. When sown indoors, transplant them into the garden 6-10 inches apart.

How to Care for Ageratum

Ageratum is a low-maintenance plant, and it will readily fill in garden beds as long as it has enough water. Ageratum will bloom consistently on it’s own without the need of deadheading as old blooms will naturally fall off as new blooms arrive. Ageratum flowers less vigorously in hotter environments. Roots may rot in poorly draining soils. Powdery mildew may be present if overhead watered, so watering around the roots of the plant is advised. Ageratum grows best in areas with good air circulation.