Winterizing Hydrangeas: How to Winterize Hydrangeas

Hydrangeas are hardy and frost-resistant flowering plants. They thrive as perennials in USDA Hardiness Zones 3–7, despite the winter temperatures in these planting zones, which can drop as low as negative forty degrees Fahrenheit. 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.

Most types of hydrangeas are cold-hardy, and practicing common winter care techniques (like mulching) primes them to survive through the winter and into the next year. When overwintering your plant, consider the hardiness of the specific variety. Monitor for signs of winter damage (such as cracked, dry bark) during the colder months. Consider these other gardening tips for overwintering your hydrangeas:

1. 1. Clean up your fall garden. Late fall is an ideal time to clear an excess of organic matter out of your garden. Rake up dead leaves to make space for new mulch, and eliminate hiding spaces for rodents and insects, which can harm your plants over the winter.
2. 2. Water before the first frost. Water your hydrangea plants regularly before the first frost of the season arrives. Pre-winter watering enables their root systems to retain moisture throughout the winter. Avoid fertilizing your hydrangeas right before winter because feeding is ineffective during dormancy and can cause new growth to sprout before the spring warmth.
3. 3. Lightly prune the plants. New wood bloomers—like oakleaf hydrangea, Annabelle hydrangea, panicle hydrangea, or H. arborescens ‘Grandiflora’ hydrangea—require pruning in early spring. However, you should prune some old wood blooming hydrangeas—such as climbing hydrangeas or bigleaf hydrangeas (Hydrangea macrophylla) like lacecap hydrangeas and mophead hydrangeas—at the end of the growing season in early fall to prepare for the winter. Simply remove any dead or damaged branches, flower heads, and flower buds. Prune hydrangea plants lightly for a more prodigious bloom the next season.
4. 4. Add a thick layer of mulch. At the beginning of winter, place several inches of mulch—organic material like shredded leaves, sawdust, straw, and wood chips—around the base of the plant. Mulching enables its roots to stay warm throughout the winter months and into early spring and prevents sprouting in the winter, which can happen as the ground freezes and thaws throughout the season.
5. 5. Wrap with winter protection. During the winter, make a DIY A-frame wire cage out of burlap and chicken wire to protect your hydrangea plant. This cage will protect it from winter winds, heavy snowfall, and cold temperatures.

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