Thanks for writing. I'd feed your plant a little --- in containers there's no way for the soil to replenish its nutrients like it does in the ground, so if your plant has been in the pot for 10 years, I'd guess it's getting hungry. Has it been in the same pot for 10 years? It may need a bigger pot, too --- being rootbound can keep it from blooming well.
---Justin, Senior Garden Editor, BHG.com "