I bought a wisteria last year from b&q and was told to trim back in August, which I did. This year I made a umbrella frame and potted it in a larger pot. Is it to late to trim back now? I haven't had any flowers this year and didn't expect any as it was only a young plant. Should I leave it this year to fill up the frame?or can I still prune it ?I heard if you prune, it encourages flower buds for the following year. I can't wait till I get my first flower.