Hydrangea Winter Care: Protecting Your Summer Blooms

Hydrangeas are beloved for their stunning blooms and lush foliage, but winter can pose challenges for these beautiful plants. Proper winter care is essential to ensure your hydrangeas thrive and bloom beautifully when spring arrives.

Know Your Hydrangea Type

Before diving into winter care, it’s essential to understand the different types of hydrangeas, as their winter needs can vary:

• Hydrangea macrophylla (Bigleaf Hydrangea): These hydrangeas are particularly sensitive to cold and can suffer from winter damage if not properly cared for. They bloom on old wood, so protecting them is crucial. USDA Hardiness Zones: 5-9.
• Hydrangea paniculata (Panicle Hydrangea): More tolerant of cold temperatures, these hydrangeas bloom on new wood and are generally easier to care for during winter. USDA Hardiness Zones: 3-8.
• Hydrangea arborescens (Smooth Hydrangea): These are also more resilient and bloom on new wood, making them less susceptible to winter damage. USDA Hardiness Zones: 3-8.
• Hydrangea quercifolia (Oakleaf Hydrangea): This variety is known for its unique oakleaf foliage and can handle cold climates but still benefits from winter protection. USDA Hardiness Zones: 5-9.
• Hydrangea serrata (Mountain Hydrangea): Similar to Bigleaf hydrangeas, they require protection during winter. USDA Hardiness Zones: 6-9.

Nikko Blue Hydrangea – Hydrangea macrophylla or Bigleaf Hydrangea

Preparing Hydrangeas for Winter

Proper preparation is key to ensuring your hydrangeas survive the winter months. Here are steps to take in the fall:

Watering: Ensure your hydrangeas receive adequate water leading up to winter. Like all perennials, shrubs or trees, Hydrangeas need to be well-hydrated before the ground freezes. Water deeply if there hasn’t been sufficient rainfall in late summer or early fall.

Mulching: Apply a layer of mulch (about 3-4 inches or 7-10 cm) around the base of the plants. This helps insulate the roots and retain moisture. Use organic materials like wood chips, straw, or shredded leaves to provide insulation and reduce temperature fluctuations in the soil.

Pruning: Hydrangeas that bloom on old wood should avoid heavy pruning in the fall. Such pruning should occur just after flowering. Instead, remove only dead or damaged wood. Old wood bloomers include:

• Hydrangea macrophylla (Bigleaf Hydrangea),
• Hydrangea serrata (Mountain Hydrangea),
• Hydrangea quercifolia (Oakleaf Hydrangea).

Hydrangeas that bloom on new wood can be pruned back in late winter or early spring. New wood bloomers include:

• Hydrangea arborescens (Smooth Hydrangea)
• Hydrangea paniculata (Panicle Hydrangea).

Limelight Hydrangea – Hydrangea paniculata or Panicle Hydrangea

Protecting Hydrangeas in Winter

Once you’ve prepared your hydrangeas for winter, protecting them from harsh weather conditions is essential. Here are effective methods to ensure their safety:

Covering: For more delicate varieties, consider covering the plants with burlap or frost cloth during particularly cold snaps. Ensure enough ventilation to prevent moisture buildup, which can lead to rot.

Wrapping: For small to medium-sized hydrangeas, you can wrap the base with burlap to provide extra insulation. You can also create a cage around the plant and fill it with leaves or straw for additional protection.

Caging: For larger hydrangeas, construct a cage using wire fencing or stakes and fill it with mulch or straw. This creates a protective barrier against freezing temperatures and wind.

Location Consideration: If you live in a particularly cold area, consider planting your hydrangeas in a more sheltered location, such as near a south-facing wall, which can provide extra warmth.

Potted Hydrangea: Potted hydrangeas thrive during winter when kept in a garage or basement where temperatures remain cool but above freezing. Although the plants will enter dormancy, it’s essential to water them occasionally—approximately once a month—to keep the roots moist until spring arrives.

Peegee Hydrangea – Hydrangea paniculata ‘Grandiflora’

Maintaining Hydrangeas During Winter

While hydrangeas are dormant during winter, there are still maintenance tasks that can help ensure their health for the coming season:

Monitoring: Check on your hydrangeas periodically throughout the winter. Look for signs of damage, such as wilting or browning leaves, and adjust your protective measures if necessary.

Watering: If you experience a thaw during winter, consider giving your hydrangeas a drink of water, especially if the soil appears dry. However, avoid overwatering, as this can lead to root rot.

Preventing Snow Damage: If heavy snowfall occurs, gently shake off excess snow from the branches to prevent breakage. Avoid using sharp tools, as this can damage the plant.

Annabelle Hydrangea – Hydrangea arborescens or Smooth Hydrangea

Common Issues in Winter Care

Winter Burn: This can occur when the sun and wind dry out the leaves. Using burlap to shield the plants can help reduce exposure.

Root Rot: Ensure good drainage to prevent water from sitting around the roots. Overly wet soil, especially during thaw periods, can lead to root rot.

Fungal Diseases: Mold can develop if the plants are too wet or covered too tightly. Allow for airflow by ensuring covers are not tightly wrapped.

Signs of Spring

As winter begins to transition into spring, look for signs that your hydrangeas are waking up from dormancy:

Buds Swelling: As temperatures begin to rise, you may notice the buds starting to swell. This is a good sign that your hydrangeas are ready to grow.

New Growth: As the danger of frost passes, new leaves will begin to emerge. This is a crucial time to monitor for pests or diseases.

Pruning: For varieties that require pruning, now is the time to shape and trim your hydrangeas for optimal blooming.

Strawberry Vanilla Hydrangea – Hydrangea paniculata or Panicle Hydrangea

Frequently Asked Questions

Should hydrangeas be cut back for winter?

It depends on the type of hydrangea. For those that bloom on old wood, like Hydrangea macrophylla (Bigleaf) and Hydrangea serrata (Mountain), avoid heavy pruning in the fall, as this can remove flower buds. Lightly trimming dead or damaged stems is acceptable. For hydrangeas that bloom on new wood, such as Hydrangea paniculata (Panicle) and Hydrangea arborescens (Smooth), you can cut them back in late winter or early spring.

What should I do with my hydrangea in the winter?

Ensure hydrangeas are properly prepared for winter by watering them before the ground freezes, applying mulch around their base for insulation, and covering delicate varieties with burlap or frost cloth during severe cold snaps. Monitor them occasionally for damage and maintain adequate moisture levels.

What happens if you don’t cut back hydrangeas?

If you don’t cut back hydrangeas, particularly those that bloom on old wood, you may end up with an unruly plant that can be prone to disease. Overgrown hydrangeas can also experience reduced blooming since old, dead, or damaged wood may limit flower production.

Should I cut my hydrangea down to the ground?

Generally, you should not cut hydrangeas down to the ground, especially if they bloom on old wood. This practice can remove flowering buds and result in fewer blooms in the spring. For new wood bloomers, you can cut them back significantly, but always check the specific needs of your hydrangea type.