Ageratum is seen everywhere during the summer months. The compact plants and the neat powder-puffcover 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 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 Angel’ (-blue) and ‘Blue Blazer’ (deep blue). The ½ ft ‘Blue Bouquet’ is the giant, and the non-blues include ‘Summer Snow’ (white) and ‘Fairy Pink’ (rose).
SITE AND 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.