pruning problem hydrangea

Asked January 11, 2018, 5:19 PM EST

For a couple of years, my large hydrangea has bloomed almost entirely around the bottom, with very few blooms in the upper parts. Individual heads are huge and weigh down the branches. How should I prune to encourage flowers at the top?

Jackson County Oregon hydrangea pruning shrubs horticulture

2 Responses

Most hydrangeas should be pruned after blooms fade in fall. Do not prune any branches that have not bloomed, as they may bloom the following year.( Hint: the top branches may be new wood and your particular hydrangea may bloom only on old wood--if you cut back the entire plant, you may lose those potential blooms.) You can also wait until late in the dormant period (end of February to mid-March) to cut the branches that have bloomed to a point just above the base of the previous year's growth, leaving two buds. Again, spare those branches that did not bloom. This process should yield you flowers all over the plant. Dead branches should be totally removed, of course. One pruning guide suggests that if things get really awry, cut the whole plant to the ground and let it start over!

As for the size of the flowers, some "mopheads" can reach one foot or more in diameter. With stems that are weak, they will flop despite what you do. Or you may be cutting too much, leaving only a few blooming branches. With no competition, bloom size will be larger. Leaving more branches will give you smaller, but more abundant blooms. Some of the newer cultivars ('Pink Beauty';'Twist and Shout';'Limelight') may give you two sets of bloom in summer and fall. 'Endless summer', a popular choice, blooms only on new wood. Thanks for using Ask an Expert. Enjoy your hydrangeas!

Thanks. I'm going to have to print this out and go out and study the plant to see how it applies. Very comprehensive!