A common question our nursery staff hears quite often is: “why aren’t my hydrangeas blooming?” Though it’s not uncommon for hydrangeas to have this problem, the answer isn’t very cut and dry. We’re here to provide some insight on what is causing your hydrangeas to not flower, as well as what to do to get them blooming again.
First, it’s important to know that there are three types of hydrangeas when it comes to how they bloom:
- Those that bloom on old growth
- Those that bloom on new growth
- And the Endless Summer series, which bloom on both
If you’re not sure what type of hydrangea you planted, you can figure it out a couple of different ways.
When did they bloom? Hydrangeas that flower on old growth with bloom in early summer and finish by midsummer. Those that flower on new growth will flower from midsummer to first frost. If your hydrangea blooms from early summer to fall, it’s more than likely an Endless Summer hydrangea.
Can’t remember when they bloomed? That’s okay. You can tell what type they are by what kinds of flowers they produce:
- If your hydrangea has big pink or blue flowers, treat it as an old growth hydrangea
- If the flowers are round and white, treat is as a new growth hydrangea
- If the flowers are large, conical, and white, pink, or green, treat it as a new growth hydrangea
Pruning Old Growth Hydrangeas
Prune old growth hydrangeas as the flowers begin to fade. The earlier you prune the spent flowers, the more energy your hydrangea can push into producing buds for next year. Don’t prune these to the ground in late
fall or early spring! Doing so will remove all of next year’s flower buds.
Pruning New Growth Hydrangeas
Cut your new growth hydrangeas all the way to the ground in late winter/early spring. They’ll produce larger blooms if they’re pruned back hard like this every year.
Pruning Endless Summer Hydrangeas
Prune these like old growth hydrangeas. Remove spent flowers as they fade to promote new buds for next year. If you forget to remove old flowers in the fall, no worries. You can prune it in the spring, but remember that you’re cutting off possible flowers for that season. You’ll still get blossoms in late summer since they produce on new growth.
But what if I didn’t prune? I still don’t have flowers!
If your hydrangea was planted within the last year or two, it’s not uncommon for it not to bloom. Newly planted shrubs focus energy on developing their root systems rather than flowers, so give your hydrangea a year or two to develop to see flowers.
Hydrangeas won’t produce blossoms in heavy shade. Some varieties can take partly shady areas, but if your hydrangea doesn’t receive more than 4 hours of sunlight, consider moving it to a sunnier spot.
Over-fertilization is also a cause for a hydrangea not to bloom. Fertilizing too often can cause a hydrangea to focus on producing nice, lush leaves over flowers. Feed your hydrangeas once this month with an acidic fertilizer such as Holly-Tone, and then leave it. Holly-Tone is a slow-release fertilizer so you’ll reap the benefits longer through the season!