Penstemons to me are a great plant to have in any size garden, they flower all summer long and are loved by bees. They come in such a wide range of colours as well as well as being so easy to look after as well. They are one of those plants that don’t need much pruning other than removal of spent blooms during the summer to encourage a longer flowering season. But if they are left alone, they can get rather woody and well just ugly if I do say, one thing I can’t stand in the garden are plants that look ugly, it’s bad enough having me around the place! So I have found the best way to keep them looking fresh and young during their short 5-7yr life span. I like to leave it until now with some new growth coming from the base, alsok the worst of the frost will have disappeared and while they are hardy in all but the coldest weather, I like to leave the older stems on offering some protection to the new growth. I then simply prune the old stems down to the base or near some new shoots using my sharp secateurs and then remove it. Pretty simple but can make a massive difference to the appearance of the plant. Other plants like fuchsias, Melianthus  can be treated this way but I like to do those in early May when the growth is a little longer and a bit hardier against any late frosts.