Ageratum

Unlike most Ageratum the Artist series will bloom through the summer in hot climates. The Dallas Arboretum has used Artist ageratum for years in very prominent locations with great success. They are good in pots or in the landscape. Old flowers should quickly become buried under new flowers so the plant always looks fresh and never looks old. The plants shouldn't need much, if any, maintenance. However, if the plants do become ratty or start to overgrow their location you can trim that back at any time. They will flush back into bloom in a week or so. 
Exposure
Part Sun to Sun
Height
8-12"
Spacing
10-12"
Uses
Use in combinations, window boxes and landscaping
Features
Small, fluffy, blue button-like flowers add color all season; no dead heading needed