Penstemon 39sour grapes39 features attractive bell45shaped flowers on upright spikes in an unusual pink and blue blend which is neither one colour nor the other the remarkable colouring makes this hardy semi45evergreen perennial instantly recognisable adding real impact to your garden penstemon are an excellent choice for wildlife areas and herbaceous borders where they will attract pollinating insects and add a splash of colour all summer long penstemon 39sour grapes39 i