I have been doing an experiment the past few seasons to extend or delay my Hydrangea tree’s bloom time. In the picture below, the bottom half of the tree was pruned back the 3rd week in June while the top half was pruned back the 2nd week in July. In turn this pushes the bloom time back. The rule of thumb is that this can be done on the Panicle or Annabelle Hydrangeas. Do not prune back traditional macrophylla Hydrangeas and expect blooms the same year (although some new hybrids allow this).
Another benefit to pruning the stems back by 1/2 the length, is that the shorter stems have less tendency to bend which allows the flowers stay vertical (which I prefer).
So if you’re looking to time Hydrangea blooms for a party or to just extend the blooming season in your garden, don’t be scared to cut Hydrangeas back early in the season.
Happy Gardening!
