I have 2 Hydrangeas MH. 1 is just starting to bloom. The other 1 shows no sign of blooming. With the approaching frost, is there something I should be doing now to protect the plant?
Since some varieties of the Mophead Hydrangea (Hydrangea macrophylla) can be susceptible to the cold in our zone, it is likely that the one that isn’t blooming suffered some winter kill. A late spring freeze or improper pruning are also common causes of H.m. failing to bloom.
It is probably a good idea to construct a burlap barrier around the plants to protect the flower buds from drying out. You may also want to put down a thick layer of mulch to protect the roots from the winter cold. Be sure not to push the mulch up to the stem as this can invite pests and vermin. Leave a couple inches distance between the mulch and the stems.
This should help to ensure they bloom next spring.