The two plants were planted nearly two years ago and both grew well. They initially both flowered and the red/white one continues to produce flower stems. However the purple one next to it produces profuse greenery but no more flowers.Would cutting it back hard be likely to provoke flowering or can you suggest any other remedy. I am afraid I can't remember the variety names.
02 November 2013 01:15 AM
I wouldn't be too concerned at this stage that it is not flowering. The purple flowering Penstemon may need some encouragement to flower, so why not try giving it a little sulphate of potash to encourage it to do so. Penstemon flower for quite a number of months so apply the potash every month from now on in and I am sure it will bloom for you. I wouldn't cut it back. Just give it a little time for the fertiliser to work and I am sure you will be rewarded.