When to Prune Your Hydrangeas

As you’re winding down gardening during the colder weather, it’s a great time to think about pruning your plants. Knowing exactly when to prune plants can be tricky, and varies plant by plant, prompting many questions for home gardeners. Specifically, many want to know if winter is the best time to prune hydrangeas, or if it should be prior to cold weather.

The answer to that depends on what hydrangea you have. Kemper Center staff recommend keeping nursery labels for all perennials, trees, and shrubs, or tracking the names of the plants in your garden in a journal or spreadsheet.

For pruning purposes, it’s important to know if your hydrangeas fit into one of two main groups – those that bloom on old wood and those that bloom on new wood.

Plants of Merit, Panicle Hydrangea Pinky Winky
Panicle hydrangea | Photo by Claire Cohen

Hydrangeas that grow on new wood include smooth hydrangea and panicle hydrangea. These plants can be cut back to the ground in the winter, before new growth appears in the spring.

Hydrangeas that bloom on old wood, which include lacecap or mophead hydrangea, mountain hydrangea, and oak leaf hydrangea, should be pruned in the summer. Prune the plants after the flowers fade, but don’t wait until fall to prune these hydrangeas because it could encourage new growth that won’t have time to develop before winter.

Some newer hydrangea cultivars may not fit exactly into either category because they are hybrid crosses of multiple species. Typically, these plants are marked as “reblooming,” or blooming on both old and new wood.

Japanese_Garden_Incrocci13
Panicle hydrangea in the Japanese Garden | Photo by Tom Incrocci

The benefit of these newer varieties is that the plant will still bloom even if buds are damaged in winter. The best bet is to deadhead these hydrangeas throughout the summer to encourage continuous blooming, and then prune them for shape in late fall to early spring.

For more gardening tips, visit our Gardening Help page.

 

Catherine Martin
Public Information Officer

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