Q.Why is my Pink Fountain Gaura not flowering?
Last year it gave me pink flowers. Then in the winter, I cut off the dead stems. Then this year, the plant grew green leaves with a thick trunk. The leaves do not look like the same plant from last year. How did this happen, and has it evolved?
You can try adding a boost of Phosphorous to encourage blooming.
Bone Meal is a good way to do this.
Since the Pink Fountain Gaura is a hybrid, it is feasible that it could revert to a variety that it is cross pollinated with.
It does happen in some plants.
Here is a link to refresh you on the care requirements.