Several factors will affect hydrangea blooming. Young plants may only produce a few blooms in their first couple of years. If improperly pruned or pruned at the wrong time, flowering buds can be accidentally removed, and without flowering buds, there will be no flowers. If the winter was severe, varieties that bloom on old wood may have had their flower buds killed. Too much nitrogen in the soil, possibly from a fertilized lawn, will encourage green growth at the expense of flowers.
You can send our horticulturalist pictures at custserv@burpee.com for further assistance.