A Hydrangea that won't flower
I have a large hydrangea that was in a pot for several years, and flowered really well, three years ago the flowers were so big I had to prop them up with twigs. Since then, it's sulked, no flowers while in the pot, so I thought it might be pot bound. I moved it last year to a semi shade spot, with lovely soil, and pruned it at the right time, but still no flowers. It has lots of new leaves shooting already, so what could I do to encourage flowers please? I haven't cut it back yet.