Description Penstemon ‘Sour Grapes’ A large leaved perennial, which bears large tubular bell shaped greyish blue flowers, suffused rich purple and tinged green, which are borne from mid-summer to mid-autumn. Grow in fertile, well-drained soil in full sun or partial shade. Dead-head after flowering to maintain vigour. It will reach a height of 60cm and a spread of 45cm.
