oakleaf hydrangea not blooming

(Question)

My Oakleaf Hydrangea bloomed last year but this year I see no blooms at all.  I am in Toronto.  It gets about three to four hours of afternoon sun each day.

(Answer)

Many species of hydrangea have been blooming prolifically this year in Toronto, which is a wonderful sight.  So why doesn’t your oak-leaf hydrangea (Hydrangea quercifolia) have any blooms?  You are not alone, my own oak-leaf hydrangeas have not bloomed this season.

The reason is most likely weather related.  You can probably blame it on the prolonged cold weather we endured last winter.  The blooms on Hydrangea quercifolia form on old wood (last summer’s growth).  Since oak-leaf hydrangeas are actually native to S.E. North America, where winters are generally milder, the buds that were formed last year were, no doubt, killed by our frigid arctic temperatures.  Your hydrangea may also have suffered some die-back of branches, which would have been pruned back to the ground or to emerging leaves this spring.

Unlike other hydrangeas which bloom on new wood, oak-leaf hydrangeas generally do not need to be pruned except to limit their size or direct the shape.  When necessary, branches can be pruned back half-way as the flowers fade.  Assuming that you did not prune your plant last year or this spring, the buds simply froze and therefore could not produce any flowers.  If we have a more temperate winter this year, you can look forward to your plant blooming next summer.