How and When to Deadhead Hydrangeas for Stronger Flowers That Bloom All Summer Long

Removing spent flowers will ensure your hydrangeas produce healthier, more bountiful blooms later on.

bright pink hydrangeas in the summer — Credit:
yaxxcom / GETTY IMAGES

Deadheading hydrangeas helps them produce more flowers and keeps them looking nice all summer.
The right time to deadhead depends on the type of hydrangea, either new wood or old wood.
Be careful not to cut old wood hydrangeas too late, or you could remove next year's flower buds.

Hydrangeas are known for their showy flower heads that bloom from spring until fall in a range of colors. One way to ensure your hydrangeas continue to flower throughout their blooming season is to remove dead flower heads.

Deadheading redirects the plant's energy towards producing new flower heads, leading to an abundant and extended display of blooms. Ahead, we spoke to gardening experts who shared their tips for how to deadhead hydrangeas the right way.

Melinda Myers, gardening expert, author, and host of the Great Courses' How to Grow Anything DVD series
Lorraine Ballato, hydrangea expert and author of Success With Hydrangeas: A Gardener's Guide
Jim Putnam, plant expert for Southern Living Plant Collection, a plant collection designed to solve landscape challenges

Benefits of Deadheading Hydrangeas

Deadheading allows the energy produced by the plant to go into producing new flower heads, rather than producing seeds. This extends the flowering season and encourages plant growth. In addition to bolstering future blooms and strengthening stems, deadheading your hydrangeas has aesthetic benefits, too.

"Removing faded flowers creates a neat and tidy appearance, which many gardeners prefer over the look of leaving dried flowers on the plant," says Melinda Meyers, gardening expert and host of the Great Courses' How to Grow Anything DVD series.

When to Deadhead Hydrangeas

When and how you deadhead hydrangeas depends on the variety you’re growing: old wood or new wood. It’s also important to know if your hydrangea is a re-blooming variety.

Deadheading New Wood

New wood species include: some big leaf hydrangeas, some mountain hydrangeas, all smooth hydrangeas, and all panicle hydrangeas. You can deadhead new wood plants during the growing season.

“Just be sure to stop by about August 15 so as not to over-stimulate the plant when it should be focused on settling down for a winter rest,” says Lorraine Ballato, a hydrangea expert and author of Success With Hydrangeas: A Gardener's Guide.

You can also deadhead new wood species once they are dormant, which means they have dropped all their leaves. This is typically during fall, winter, and early spring. "If you wait too long in spring, you run the risk of cutting off the newly developed flower buds for the current season," says Ballato.

Deadheading Old Wood

Old wood species include all big leaf hydrangeas, all mountain hydrangeas, all oak leaf hydrangeas, and all climbing hydrangeas. You can deadhead old wood varieties during the growing season, but it’s not necessary. If you do, make sure you stop by August as this is when the plant starts to set its buds for next year, says Meyers.

There is a case for leaving the flowers growing on old wood varieties rather than deadheading them. “The dead flowers act as an umbrella and protect stems and buds further down the plant during winter,” says Ballato. “Those dead flowers can also be quite beautiful in the winter as they catch snow and ice and glisten in the winter light.”

Improper timing matters the most for old wood hydrangeas because cutting back too late in the season can remove next year’s flower buds, which form on last year’s growth.

Deadheading Reblooming Hydrangeas

Reblooming hydrangeas, like White Wedding hydrangea, should be deadheaded right after they finish their spring or summer blooming cycle, but deadheading isn’t necessary, says Jim Putnam, plant expert for Southern Living Plant Collection. If you are going to deadhead reblooming varieties, do not wait too long, or you will miss your reblooming window, says Ballato.

How to Deadhead Hydrangeas

Varieties that bloom on old wood do not require any deadheading except to control bloom height or to tidy up the plant. Locate spent blooms and then follow them down to the first set of full-sized leaves beneath the flower head—make your cut right above the leaves.

You can be more aggressive when deadheading hydrangeas that bloom on new wood. Follow the same method for old wood, above, but you can cut further down the stem to the next set of leaves for a more dramatic cut.

For the best results when deadheading hydrangeas, ensure that you use clean, sharp pruning shears. Dull or unclean shears can damage the stems or introduce disease to the plant, which could affect future blooms.

Frequently Asked Questions

Will not deadheading new wood hydrangeas hurt the plant?

No, you will not hurt a new wood hydrangea plant if you decide not to deadhead it. The blooms will naturally fade and fall off on their own over time. In fact, leaving the spent flowers can add winter interest and, on old wood hydrangeas, even protect the plant’s new buds from frost.
What should I do about the sticks in my hydrangea plant?

Remove those sticks or dead stems in the early spring before the new growth or blooming begins to tidy up the plant. This cleanup won’t affect flowering and helps direct energy to healthy new growth. To tell if a stem is actually dead before removal, do a quick scratch test—if the tissue beneath the bark is brown and dry instead of green, it’s likely dead.
What should I do if I missed the window to deadhead hydrangeas?

You can either leave the plant alone or remove the dead parts from the plant for aesthetic purposes. If you do not take the dead parts off, they will decompose on their own.