Hydrangeas may not bloom for a variety of reasons. Gardeners are often disappointed when a bush that bloomed well in the previous year doesn’t bloom at all the following year. While hydrangeas prefer afternoon shade during our hot summers, they won’t have the energy to produce many blooms if they are in too much shade. A tree that has grown up and blocked the sun may be the culprit. Panicle hydrangeas such as “Limelight” and “Bobo” need up to five hours to bloom their best. Macrophylla hydrangeas such as “Endless Summer” need much less and can bloom with only 3 hours of direct sunlight.

Hydrangeas may also fail to produce blooms if a hard freeze kills the buds for the following year’s flowers. Older varieties, such as Nikko Blue, will fail to bloom if frozen back to the ground. Mounding mulch up to 12” high around the base during the winter helps insulate them through the winter. Wait to remove the mulch until all danger of frost is past. It is also recommended not to prune hydrangeas after August 1st to avoid removing dormant flower buds for next year. This is not nearly as much of a concern on Panicle Hydrangeas. Occasionally hydrangeas still won’t bloom despite precautions taken. Sweltering summers can often reduce blooming. Feeding hydrangeas with compost in the spring and mulching 2 to 3 inches deep helps the roots conserve water and put on much more of a show.