As the crisp autumn air gives way to winter's chill, gardeners across the UK are being advised to take immediate action to protect one of their most beloved shrubs. Hydrangeas, celebrated for their voluminous and colourful blossoms, are particularly susceptible to damage from frost, which can jeopardise next year's floral display.
Understanding the Frost Threat to Your Blooms
The danger lies in the freezing temperatures themselves. Frost causes the water within a hydrangea's plant cells to freeze, leading to ruptured cell walls. This cellular damage manifests as wilting, blackened and crispy leaves and buds, and can even kill off new growth and the precious buds destined to become next season's flowers.
The Crucial First Step: Identify Your Hydrangea Type
Before you begin any protective measures, it is vital to identify whether your hydrangea blooms on old wood or new wood. This distinction, highlighted by sources like Southern Living, dictates your pruning strategy. Old wood hydrangeas form their flower buds during the summer's active growth phase. In contrast, new wood hydrangeas produce blooms on the new growth that emerges in the spring.
This classification is crucial for timing your pruning correctly. Prune old wood varieties right after they finish blooming in the spring and summer. For new wood varieties, pruning is best done when the plant is dormant in the winter.
Five Vital Steps for Winter Protection
To ensure your hydrangeas survive the winter and return bigger and healthier next spring, follow these five essential steps.
1. Eliminate Damaged or Diseased Branches
Start by carefully inspecting your plant. Remove any branches that show signs of damage or disease. This helps to prevent problems from spreading and allows the plant to direct its energy towards healthy growth.
2. Prune with Caution
Exercise restraint with your secateurs. For hydrangeas that bloom on old wood, you should refrain from pruning them now. For those that bloom on new wood, it is advisable to hold off on any pruning until after the first frost of the season has occurred.
3. Collect Dried Blooms
Gently collect any dried, spent blooms from the plant. This not only tidies up its appearance but can also help prevent the harbouring of pests or disease over the winter months.
4. Water Thoroughly
Give your hydrangeas a deep and thorough watering before the ground freezes. It is essential to ensure the soil is moist to a depth of at least three inches. For gardeners with potted hydrangeas, remember to water them about once a month throughout winter to maintain moist soil, doing so during the day when temperatures are above freezing.
5. Apply a Protective Mulch
Mulching is one of the most effective ways to safeguard your hydrangeas. A good layer of mulch will insulate the roots from the coldest weather. This step is equally beneficial for plants in containers. Always ensure you leave a two-inch gap around the main stem to avoid potential rot issues.
By following this expert advice, you can shield your hydrangeas from the winter elements and look forward to a spectacular show of colour when spring arrives.
