I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
The amount of sun the plants are getting can affect bloom. Let me also refer you to the following web sites for a lot more growing tips on these plants. This may help you determine what your plants are lacking:
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
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