However, stop deadheading hydrangea shrubs in mid to late fall, leaving any spent blooms in place. This not only provides winter interest, but also ensures you don't remove the buds that will become flowers next spring.
The best time to deadhead is when the first set of blooms on your hydrangeas begin to turn brown and dry. Cut the stem below the flower head and just above the first set of leaves. For reblooming types, you can deadhead again when this second set begins to fade, but only through mid-August or so.
Removing spent flowers will ensure your hydrangeas produce healthier, more bountiful blooms later on.
No need to prune.
Leaving the old flower heads on the plants will also add some interest to the winter landscape. It's best to save hydrangea pruning chores until spring or summer after plants bloom (don't worry, the new growth will soon hide any dead stems from the following year).
6. What to do if your hydrangeas have brown flowers? Clip those toasted blooms off, snipping just under the browned flower. Removing browned petals improves the look of the plant and for re-blooming varieties helps to promote the production of more flowers.
If your hydrangea blooms are turning brown too soon and quickly petering out, they likely need more water. Ditto if your flowers wilt during the day and don't bounce back at night. To confirm, look for brown spots on leaf edges. To fix, deeply water hydrangeas once a week.
Shallow or inconsistent watering.
If a hydrangea is being watered every other day for twenty or thirty minutes (sadly, standard automatic irrigation settings) the plant is likely to wilt in hot weather. Once the flowers wilt a few times they will turn brown.
To prepare hydrangeas for winter in colder areas, add a thick layer of mulch around the base of the plants to protect the crown and roots from freezing temperatures.
To reduce the size of a hydrangea that blooms on new wood, cut off about one-third of each stem in late fall or early spring before it begins to leaf out. If your hydrangea blooms on old wood, prune right after it has bloomed when the flowers are fading.
Cut the dead stumps down to their base to completely remove them. This will allow the new growth underneath to have a chance to succeed. Dead and old blooms need to be removed to make room for new buds to come through. Cut the flower head off right above the first few leaves to encourage blooms for the next summer.
Without going through the deadheading process, hydrangeas will not produce as many flowers and the few produced may not grow as big to their full potential.
Know when they're beyond repair.
If you catch and treat your hydrangeas when their blooms first start turning brown, Myers says there's a good chance you'll be able to turn them around (as long as it's not due to weather damage). "However, once they turn fully brown, there's not much you can do," she says.
If you don't prune hydrangeas then they can eventually resemble a tangled mass of woody stems, and the flowers will become smaller and less showy.
"Stop deadheading in the fall, when bigleaf hydrangeas produce their last flush of flowers, to enjoy the dried blooms throughout the winter," she says. "These can be removed to help produce healthy buds in the spring."
While some plants bloom on new growth, others primarily set flower buds on old wood. Regardless, it is best to wait to prune all hydrangeas until spring. In the fall, hydrangeas (and all trees and shrubs) are in the process of going dormant. They do not produce very much new growth until the following spring.
To rejuvenate the hydrangea, remove up to 1/3 of the older living stems down to the ground each summer. This will revitalize the plant. If necessary to control the size of the plant, cut back before late July to allow for buds to develop. Usually the plant will return immediately to its former size.
Wrap with winter protection.
During the winter, make a DIY A-frame wire cage out of burlap and chicken wire to protect your hydrangea plant. This cage will protect it from winter winds, heavy snowfall, and cold temperatures.
Provided that you give your reblooming Hydrangeas the proper care, you may have blooms that last until the first frost. Reblooming varieties extend the season through the fall because a second set of buds form on the new wood creating a second bloom.
Some gardeners report success in turning their hydrangeas blue by applying coffee grounds to the soil. The coffee grounds make the soil more acidic, allowing the hydrangea to more easily absorb aluminum.
Should I Cut Off Brown Hydrangea Leaves? The short answer is, “it depends.” While damage to leaves is unsightly, they can and will recover if you identify the problem and implement the solution early enough. As a general rule of thumb, we recommend removing leaves when they are 50% brown or higher.
Here's what to look for: Leaf discoloration: hydrangea laves typically become yellow and brown when overwatered. However, the discoloration can also be a sign of underwatering. Usually, when the plant is overwatered, the browning occurs on the edges of the leaves.