This hardy perennial's semi-evergreen foliage is complemented by its plum coloured flowers. These bell-shaped blooms appear on upright spikes in the spring, summer and early autumn. They can be easily distinguished by their white throats, which make their purple petals appear all the more vivid. However, Penstemon 'Pensham Plum Jerkum' doesn't just look pretty. The plant is extremely weather resistant because it's been bred to survive in low temperatures. This quality allows it to continue brightening up your garden as late as October. Height: 75cm (2'6); Spread: 45cm (1'6).