Annuals Dictionary: Ageratum
Daisy family
Compositae
A-jur-a’tum. A group of nearly 30 species of chiefly tropical American annual herbs, one of which is perhaps the most popular of all edging plants.
Description
Leaves opposite, generally oval, the margins with rounded teeth. Flowers blue, pink, or white in some horticultural forms, in compact, clustered heads, without rays.
How to Grow
Ageratum is rarely direct seeded in the garden because the small seedlings can be swamped by weeds. Start seeds indoors at 70-75° F (21-24° C) and set in the garden after frost danger. Prefers full sun but where summers are long and hot, place in light shade. In moderate shade the plants will stretch. They prefer warm weather.
Ageratum Houstonianum
Common Garden Ageratum ; Flossflower . Usually 14 in. (35 cm) high. Flowerheads just over ? in. (6 mm) in diameter, blue, the outside somewhat sticky. Central and South America. There are many cultivars. ‘Album’ has white flowers; ‘North Sea’ is deep blue and blooms until late fall. Pink-flowered and dwarf varieties available. Also often sold as A. mexicanum . Tender annual.