Dear Bobbi:
My experience with Buddleia is one where if you give it plenty of
water (well drained soil) and pinch the new growth in spring you should
get plenty on flowers. These plants in my area (Cleveland OH) require
fairly good sun and plenty of watering. Since we have fairly hard
winters here my plants died back to the ground (or mostly bare twigs in
winter and early spring) and if there was anything left I pruned back to
live wood each spring and got excellent results.
My guess is not enough sunlight. All the best.
Tim Wilson
Chagrin Falls, OH
Zone 5