Penstemons are one of those plants that root easily and don’t need any special attention when you’re propagating them. If only all plants were as easy-going!
The reason many people take cuttings of penstemons in late summer and autumn is mainly as an insurance policy – they’re borderline hardy, but in particularly harsh winters they can succumb to frost, or worse, lots of winter rain clogging up their roots.
So if you want to carry on growing these splendid, long-flowering blooms it pays to increase your collection now, for free, instead of replacing plants in spring.
Plus, if you’re tempted by some lovely penstemon plants that may still be on offer in garden centres – perhaps in the bargain bin at this stage in the year – keep them indoors in a frost-free place instead of planting them out now. This will save them being unnecessarily exposed to dodgy weather over the next few months.
As for taking cuttings, choose the freshest non-flowering shoots, cut from their tips at about 15-20cm (6-8in) long, and once potted up simply let them grow on in frost-free conditions in a cold frame or greenhouse.