I have recently taken some penstemon cuttings (maybe 6 weeks ago ) and they seem to be doing ok . I have 6 in a large pot . Can anybody tell me when I would need to pot them on and what type of medium I should use . Thanks for any advice .
If the tips are growing and roots coming out of the bottom, I would pot them on singly into 10 cm pots of good potting compost. Keep them protected until spring and pinch out the growing tips to make them bush. They will not need heat, just protection from the worst of the weather, cold frame will be fine.