Penstemons are a real favourite of mine. They mix really well with most plants and flower and flower, some from June until the frosts if you deadhead regularly and give them a feed. They are really easy from cuttings and late August is a good time to take them. Take a non flowering shoot if you can about 10/15 cm, strip off the bottom leaves and put them into a pot of gritty compost. Keep them really damp for a couple of weeks, then water them often and you will get little plants well able to overwinter in a frost free or sheltered place. They should then flower next year. Its often said they area bit tender, but, apart from the very worst of winters, mine have survived here for at least 3 or 4 years. They then tend to get a bit woody and need replacing. Cutting them hard back, almost to the ground, in April, ensures their vigour for a bit longer. Pictured is Czar, an upright, fairly short penstemon. Blackbird is deep purple, taller, more elegant. Firebird is a great doer, the colour of crushed strawberries, the most generous flowerer here. For those of you who like more subtle colours there is a popular pink 'Hidcote' and 'Sour Grapes' is a kind of muddy purple (sorry, not my thing, but may be yours!). The white ones and softer colours tend to be more tender in my experience.