WHY DOESN’T MY HYDRANGEA BLOOM?
This is a commonly asked question with three possible answers. The first two – not enough sun and incorrect pruning practices – apply to all species of hydrangea. The third – weather related damage to the flower buds – is usually only the culprit of bigleaf hydrangeas not flowering.
Most hydrangeas do need shade, however too much shade can cause your hydrangea to greatly reduce its flowering potential. (For example, Hydrangea paniculata will be at its best in full sun). Bigleaf, oakleaf and smooth hydrangeas will typically do best if they are placed on the north side of a house, or at the edge of a wooded area.
Pruning incorrectly can also cause reduced flowering in hydrangeas. Bigleaf and oakleaf hydrangeas flower on previous year’s growth. This means that if you prune your plant in the fall, winter or spring, you could be removing your flower buds without realizing it! Panicle and smooth hydrangeas flower on same-year growth. Pruning them in early summer could greatly inhibit flowering for that year.
SPECIES COMMON NAME WHEN TO PRUNE
paniculata PEE GEE LATE WINTER
macropylla BIGLEAF AFTER FLOWERING
quercifolia OAKLEAF AFTER FLOWERING
anomela CLIMBING AFTER FLOWERING
sub sp. petiolaris
arborescens SMOOTH LATE WINTER
The most common reason for a hydrangea not flowering is unfavorable weather. Hydrangea macrophylla primarily flower on old wood. If your plant’s aboveground parts are damaged flowering will be reduced. This can happen from freezing prematurely in the fall, (when the plant isn’t completely dormant), harsh winter temperatures and late freezes in the spring after the plant has started to come out of dormancy. As soon as the temperatures start to become warmer in the early spring, Hydrangea macrophylla will start to come out of dormancy and produce new leaves. Damage happens when a sudden freeze occurs after the plant has started to awaken. The level of damage depends on how many buds have broken dormancy. If many buds on a branch were growing, the entire stem may be lost, and in some cultivars, this means the plant might not flower at all that season however your plant will recover the following season.
With proper placement and pruning your hydrangea should flower healthily for many years!