Have you fertilized your plant with a high Nitrogen fertilizer, if so this will encourage follage to grow at the expense of the flowers

maybe its too small and young to flower this year, I'd look after it and feed it next spring potash is for promoting flowers but if its a young plant maybe a balanced feed first for all round growth and then a high potash feed. don't feed in the autumn as you may cause a growth spurt of soft foliage which can't survive the winter

I agree, they normally make a lot of growth the first year or maybe second before flowering. Cuttings I have taken of several in the past do this always.