Can You Prune Hydrangeas in Summer Without Losing Future Blooms? Experts Explain

You can prune hydrangeas in summer, but it depends on the variety.

pink hydrangea bush — Credit:
Maryna Andriichenko / GETTY IMAGES

Pruning hydrangeas at the right time ensures healthy growth and beautiful blooms for the next season.
Old-wood hydrangeas, like bigleaf and oakleaf, can be pruned in summer right after flowers fade to protect next year’s buds.
New-wood hydrangeas, like panicle and smooth, should not be pruned in summer, as it removes this year’s blooms.

While summer may seem like the ideal time to prune your hydrangeas, it can actually be more harmful than helpful, depending on the specific variety you have. Some hydrangeas bloom on old wood, while others bloom on new wood. Knowing this helps determine the right time to prune, as doing so at the wrong time can stunt growth and reduce flower production. However, pruning the right varieties in summer can lead to healthier plants and beautiful flowers.

Ahead, experts explain the confusion surrounding summer hydrangea pruning and provide valuable tips for successful pruning so that your plants can bloom beautifully.

Rachael Kemery, a botanical grower at Rising Iris Farm
Patrick Greenwald, senior horticulturist at Longwood Gardens

Is Summer a Good Time to Prune Hydrangeas?

Whether or not you prune hydrangeas in summer largely depends on the type of hydrangea you're growing. "Before any shears come out, know your plant," says Rachael Kemery, a botanical grower at Rising Iris Farm. "Cut the wrong hydrangea type in summer, and you'll spend next year looking at a healthy green shrub that refuses to flower. With the right hydrangea type, summer is exactly the time to do it," she says.

How Different Hydrangea Types Affect Pruning

Limelight hydrangea with green flowers blooms in the garden in summer — Olga Seifutdinova / Getty Images

There are six main types of hydrangeas, which are categorized as either old wood or new wood: Panicle hydrangea (Hydrangea paniculata), bigleaf hydrangea (Hydrangea macrophylla), smooth hydrangea (Hydrangea arborescens), mountain hydrangea (Hydrangea serrata), climbing hydrangea (Hydrangea anomala subsp. petiolaris), and oakleaf hydrangea (Hydrangea quercifolia). Each one requires slightly different pruning methods.

Old Wood Hydrangeas

The primary types of hydrangeas that bloom exclusively on old wood are:

Bigleaf hydrangea
Oakleaf hydrangea
Mountain hydrangea
Climbing hydrangea

For the old-wood group, Kemery notes that summer is the ideal time to prune. But don't wait too long, as late summer pruning of old wood hydrangeas removes the newly formed flower buds for the following season. "The window you want is right after the flowers fade, as that timing gives the plant the rest of the summer to grow and set next year's buds," Kemery says.

Not sure which type of hydrangea you have? Don't guess. "Watch when it blooms, and notice whether the flowers sit on this year's new growth or last year's old growth. One season of close observation tells you what you need for every season after," Kemery says. For more, see: A Visual Guide to the Most Popular Types of Hydrangeas.

New Wood Hydrangeas

The primary types of hydrangeas that bloom on new wood are:

Panicle hydrangea
Smooth hydrangea

New-wood hydrangeas are the opposite of old wood when it comes to pruning. "Prune panicle and smooth types in late winter or early spring, before they start growing for the season, and you can cut them back hard," says Kemery. Do not prune them in the summer. "By that time, they are already developing this year's blooms, and cutting them in the summer removes those blooms before they open."

Pruning in summer forces the plant to produce tender new growth just before autumn. This fresh growth may not have enough time to harden off, making it highly susceptible to freezing and dieback in cold weather.

What You Can Prune in Summer

While you should avoid pruning summer-blooming hydrangeas that flower on new wood, light trimming is acceptable, such as deadheading and removing any dead or diseased plant material. "Anything dead, broken, or diseased can be removed as soon as you notice it, as these cuts will only benefit the plant," says Kemery. The same applies to cutting a few stems for bouquets. Below are the light summer pruning methods that can benefit your hydrangeas.

Deadheading Spent Blooms

Deadheading new wood hydrangeas is safe to do in summer. Kemery recommends snipping the spent flowers just above the first healthy set of leaves. For old-wood plants, it's best to stop there. "If you continue cutting further down for a neater shape, you'll accidentally remove next year's buds, which develop lower on the stem," she explains.

Removing Damaged Stems

Summer is a good time to remove dead and dying stems from both new and old wood hydrangeas. Trimming these damaged stems helps prevent disease and keeps pests at bay. Additionally, this practice allows the plant to focus its energy on healthy, thriving branches instead of wasting resources on unhealthy ones.

Common Summer Pruning Mistakes

bigleaf hydrangea — Catherine McQueen / Getty Images

In general, Patrick Greenwald, senior horticulturist at Longwood Gardens, recommends avoiding heavy pruning on most hydrangeas, except for Hydrangea arborescens. Heavy summer pruning can stress the plant, negatively impact its blooms, and diminish root health.

Additionally, you should wait to prune during hot, dry weather. Greenwald says pruning during cooler, wetter weather is ideal."Heavy pruning during a heat wave or a dry spell adds strain to a shrub that's low on water, and it forces out tender new growth right when the plant can least afford it," he says.

While pruning allows sunlight to reach previously shaded leaves and stems, it can also lead to scorching in hot weather. Stressed plants heal more slowly, making them more vulnerable to pests and diseases.

None of this means tiptoeing around your hydrangeas all summer, says Greenwald. "Deadhead them, tidy up any dead or broken stems, and cut yourself a few blooms for the house. Just save the real structural work for the season your particular plant is built for, once you know which one that is."