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.
But there's one key aspect of ensuring hydrangeas return bigger and better every year: deadheading. The practice of removing spent flowers from a plant, deadheading encourages stronger, more bountiful blooms later on.
Hydrangeas that bloom on old wood do not need pruning and are better off for it. If you leave them alone, they'll bloom more profusely the next season. But go ahead and gently thin or deadhead. Just remember new growth may come, but that new growth will be without blooms next season.
According to Myers, how you deadhead your hydrangeas is every bit as important as when you do it. "Locate the first set of full-sized leaves beneath the flower, and make your cut right above it," she says. "Essentially, you're removing the faded flowers to reveal a set of healthy leaves.
In addition to encouraging hydrangeas to produce more flowers, pruning these shrubs each year helps keep them healthy if they get damaged by weather and allows you to shape them however you like.
Hydrangea macrophylla, big leaf hydrangea
These plants produce buds in late summer to early fall (August-September) that will form next year's flowers. So prune these shrubs after they finish blooming before August (again, make a heading cut).
Overgrown trees can pose a serious risk to your property and your family. Dead or damaged branches can fall and cause damage to your home or car or even injure someone. In addition, overgrown trees can block sunlight and views and can even damage foundations or driveways.
However, freezing winters will push a hydrangea bush into dormancy, and it will need protection during this time. Overwintering your hydrangeas—by wrapping up the above-ground stems and protecting the root system—provides them with protection from frost or cold damage.
In colder climates, wrap or completely cover marginally hardy hydrangeas. This is especially important for those that bloom on old wood, such as mop head/big leaf hydrangeas (Hydrangea macrophylla). However, note that newer varieties of mop head/big leaf hydrangeas bloom on both new and old wood.
In certain plants, the growth node will produce more flowers in that same year. In other plants, the node will not swell until the following year. Such is the case in hydrangeas. They will not rebloom, but deadheading will clean up the plant and make way for the next year's fresh flowers.
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.
But if you do choose to prune one, remember this: Time it based on whether the type of hydrangea you have blooms on old wood or on new wood. If it blooms on old wood (stems from the summer before the current one), its buds are being formed, and if you wait too late you may cut them off, meaning no flowers next spring.
According to Hirvela, your hydrangea is done blooming when the color of the flowers has faded in a non-appealing way. "There are a few varieties that will continue to push out new buds through late summer and autumn," she says.
Both over and under-watering your hydrangeas can cause them to weaken and brown, so Myers says it's crucial be precise about irrigation. "Water established plants thoroughly but less frequently to encourage deep roots that are more drought tolerant," she says.
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.
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.
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).
Coffee grounds add extra acidity to the soil around hydrangeas. On a chemical level, this increased acidity makes it easier for the plant to absorb naturally occurring aluminum in the dirt. The effect is pretty blue clusters of flowers.