A must have plant in the garden, Penstemons are a small evergreen shrub with bell shaped flowers that cover the plant from midsummer up to the first frosts, dead heading regularly is necessary for the constant show of flowers. Raven has deep purple flowers, and is one of the earliest Penstemon. Pruning is very important, they need to be cut right back down to the ground in Spring and must not be pruned in or before winter. Penstemons are semi hardy, and the root needs the protection of the year's growth to protect it from the frost. Once Spring has begun then is the time to prune. We also suggest feeding Penstemons with tomerite after the spring prune. Tomerite has a high potassium content, this will help the plant flower constantly with epic blooms.
RHS pruning group: 7