Ageratum is seen everywhere during the summer months. The compact plants and the neat powder-puff flowers cover bare patches in borders, edge formal beds and brighten up window boxes. This popularity is largely due to the free-flowering habit and the long flowering season. The display will last until the frosts arrive if you dead-head regularly and water copiously in dry weather.
VARIETIES: The blue and mauve varieties of A. houstonianum are the most popular. There is ‘Blue Mink’ (azure-blue). ‘Blue Angle’ (lilac-blue) and ‘Blue Blazer’ (deep blue). The 1 ½ ft ‘Blue Bouquet’ is the giant, and the non-blues include ‘Summer Snow’ (white) and ‘Fairy Pink’ (rose).
SITE & SOIL: Any reasonable garden soil will do – thrives in sun or light shade. Dislikes windy, exposed sites.
PLANT DETAILS: Height 8 in. Spacing 8 in. Flowering period June – October.
PROPAGATION: Follow the Half Hardy Annual technique. Plant out when the danger of frost is past.