Surface sow and press in lightly; requires light to germinate.
Seed To Bloom:
Recommended. Sow indoors 6-8 weeks before planting out and keep at 75°F until germination occurs, then at about 60-65°F. Water from below by placing containers/trays in a larger tray of water and allow to drain; this helps prevent damping off and disturbance of seeds.
Direct sow about 1-2 weeks after the last frost for flowers mid-summer to fall.
WHEN TO SET OUTSIDE
1-2 weeks after last frost.
PLACEMENT & CULTIVATION
Dr. William Houston introduced Ageratum to England from Veracruz, Mexico, where he first collected the species in the 1700s. A reliable summer border favorite, Ageratum has handsome foliage and clusters of long-blooming fuzzy flowers that withstand summer rains. Deadheading is minimal but helpful to keep it looking fresh into fall. Pinch when setting out into compost-enriched soil and mulch to conserve moisture.
Regular watering, 1" per week.
Not particular about pH levels.
Mix in about 2" of compost and organic time release fertilizer before planting.
Diseases & Pests:
Aphids may be an issue and can be controlled with insecticidal soap. Avoid powdery mildew by placing in a location with good air circulation. Do not grow in hot & humid conditions.
When to Cut for Bouquets:
When 1/2- to 3/4 of the flowers have opened in the cluster.