How to Prune Hydrangeas

Hydrangeas provide stunning, long-lasting flowers that enhance any garden, making it challenging for gardeners to know when or how to prune their hydrangeas for the best appearance all year round.

Surprisingly, pruning your hydrangeas isn't the key to encouraging more blooms. According to Cate Singleton, design director at Tilly, an online landscaping company, "Deadheading your hydrangea is preparing it for the upcoming year," adding, "You won't see extra blooms in the current season."

Here's all the essential information on when and how to prune your hydrangeas to ensure your bushes flourish.

When to Trim Hydrangea Blossoms

Hydrangea blooms can last for months and change color over time, making deadheading a one-time task in most cases. "In warmer climates, deadheading hydrangeas helps the plant conserve energy by stopping seed production, allowing it to focus on leaf growth," says Singleton. "In colder regions, it's best to wait until spring to deadhead, as the old blooms protect the buds from frost during winter."

For mop-head hydrangeas, the ideal time to deadhead is in spring, whereas lacecap hydrangeas can be deadheaded towards the end of summer after the blooms have faded, according to Singleton.

Remember, deadheading is not essential for your hydrangea's well-being. "Deadheading is not a critical task for hydrangeas, and plants that are left without it won't experience a noticeable decline in flowering or growth in the following years," explains Jennifer Foster, a plant expert at Fast Growing Trees. "Many gardeners prefer to leave the spent flowers for winter interest, while others choose to remove them when they start to wilt, turn brown, or become ragged."

How to Trim Hydrangea Flowers

Deadheading is not the same as pruning; it involves removing the bloom without cutting into the stems, according to Foster. "Always make your cut just above a set of leaves to keep the plant neat and to improve its ability to fend off pests and diseases at the cut site. Use sharp, clean pruners and cut at an angle." Ensure your tools are sanitized to prevent the spread of any diseases to your hydrangea bush.

When deadheading hydrangeas, it’s essential to understand the specific type of hydrangea you’re working with, as both the timing and extent of cutting can vary depending on the variety.

Deadheading Bigleaf, Mountain, Oakleaf, or Climbing Hydrangea

if your hydrangea is the type that blooms on old wood, such as the oakleaf or bigleaf varieties, the buds will start forming in the old wood in late summer or over the winter, Foster says, so you'll want to be very careful not to cut too much to avoid damaging future blooms. Don't deadhead these hydrangea blooms more than absolutely necessary.

Deadheading Panicle and Smooth Hydrangea

Panicle and smooth hydrangeas bloom on new growth, so deadheading may require a more thorough approach. "You can trim back longer stems without reducing the flower count for the next year," says Foster. "These plants develop flower buds on the growth that appears in the spring. Many gardeners will cut back up to a third of the plant in late fall or early spring to promote new growth and keep the flowers closer to eye level."

Deadheading Cascade Hydrangea

Exercise caution when deadheading cascade hydrangea. "Cascade hydrangea blooms on both old and new growth, so it should only be deadheaded to the first set of leaves to maximize the number of flowers during the next blooming season," advises Foster.