Hydrangeas are one of summer’s most anticipated blooms, and having one that doesn’t flower is disappointing. Jeanine Standard of flower and plant brand, Proven Winners noted that she always gets asked about why hydrangeas are not blooming in the summer. She said: “I always know it’s July because people start calling us and asking why their hydrangeas aren’t blooming.”
The causes are as varied as the hydrangea varieties themselves, and range from not knowing how to care for hydrangeas or to prune hydrangeas to certain climate causes and more.
To help gardeners get to the root of their hydrangea woes, experts have shared their top tops for encouraging hydrangeas to bloom.
There are two common, basic reasons that hydrangeas don’t bloom – lack of sun, and lack of time.
Before you dig deeper into your investigation, rule out that one of these two issues isn’t your culprit.
Jeanine said: “There’s no such thing as a hydrangea that likes shade.”
Hydrangeas can do well in part-sun, but require at least four to six hours of direct sun exposure, and another four to six hours of indirect sun exposure per day.
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Knowing your type will help you not only to diagnose what’s going on with your hydrangeas this year, but keep them healthy so they bloom next year, too.
Hydrangeas that bloom on old wood include mountain, Oakleaf, climbing and Big Leaf varieties.
These hydrangeas flower on plant growth that was created last year.
This means that a lack of blooms this year might be from something that happened to the plant last year.
The most common reasons these hydrangeas do not bloom are down to the climate and pruning.
Hydrangeas that bloom on new wood include Panicle and Smooth hydrangeas.
They flower on growth created this year, which means that even if they get damaged there’s a chance they might still bloom this year with a little TLC.
Panicle hydrangeas are considered among the easiest to grow because they’re adaptable and flower more reliably than other varieties.
But, if your Panicle or other new wood hydrangea isn’t blooming, it’s likely not getting enough light, says Natalie Carmolli of Spring Meadow Nursery.
Panicle hydrangeas will bloom best when they get over four hours of full sun per day.
Natalie explained that getting hydrangeas to bloom is a “long game”.
She said: “You can help it out by making sure it isn’t stressed from lack of water – water deeply two to three times a week instead of a little bit each day. Add a day if it’s hotter.”
She also suggests adding a two to three inch layer of mulch around the plant to help keep roots cool and conserve moisture, and making sure hydrangeas are in an area where they’ll get at least five hours of sun a day.
Lastly, the expert noted: “Take care to cover tender buds in early spring with a sheet or light tarp, and practice proper pruning for the best flower display.
“A good shrub fertiliser, like one that’s developed for roses, will help your entire hydrangea grow more vigorously.
“But there isn’t something that you can feed it that will specifically force new buds.
“Fertilise early in the spring, and again in late spring according to package directions.”
Natalie urges gardeners not to fertilise after July, or the plant will just push new foliage growth (not extra flowers) that will not have time to harden off when the plant should be going dormant in autumn.