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?
Why Is My Pink Fountain Gaura Not Flowering?
Certified GKH Gardening Expert
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.