How to Overwinter Hydrangea Cuttings

Hydrangeas are beautiful flowering shrubs that can brighten up any garden with their lush blooms. Many gardeners like to propagate hydrangeas from cuttings to get more plants without spending a lot of money. Taking cuttings from an existing hydrangea plant is an easy way to get identical new plants.

Overwintering the cuttings properly is crucial for their survival. Hydrangea cuttings need special care to make it through the winter months when the temperatures drop. With the right overwintering method, you can have a high success rate for rooting hydrangeas from cuttings.

When to Take Hydrangea Cuttings

The best time to take hydrangea cuttings for overwintering is in late fall after the plant has gone dormant. This is usually after the first hard frost. Taking cuttings in fall allows them to avoid the hot summer temperatures and establishes them before the real cold of winter sets in.

Cuttings taken in fall or early winter are referred to as “hardwood” cuttings because the wood is harder as the plant goes dormant. Softwood or greenwood cuttings taken in summer require more controlled conditions to root successfully. Hardwood cuttings are lower maintenance.

Selecting Cuttings from a Healthy Hydrangea

Pick healthy stems from the previous season’s growth. Look for stems that are thick, mature, and do not have flower buds on them. The stems should not be soft or limp. Avoid any stems that are diseased or insect-damaged.

Cut the stems below a node or joint using sterilized pruners The cutting should be 4-6 inches long, Remove the leaves from the bottom half of the cutting Keep 1-2 leaves at the top, Dip the bottom end of the cutting in rooting hormone powder to stimulate root growth,

Overwintering Methods for Hydrangea Cuttings

There are a few techniques you can use to overwinter hydrangea cuttings so they are ready to grow come spring:

Bury the cuttings

This mimics how they grow in nature, Dig a trench in a protected location and insert the cuttings vertically with the buds facing up Space them a few inches apart, Cover with soil so just the top leaves are exposed, Add a thick layer of mulch over the trench, The ground insulation protects the cuttings from extreme cold

Place in a cold frame

A cold frame is an unheated outdoor structure with a transparent top that protects plants. Make a frame using hay bales or other insulating material Set the cuttings inside and cover with glass or plastic sheeting Ventilate the cold frame on sunny days.

Keep in a cool location

An unheated garage, cellar, or shed that stays just above freezing is suitable. Plant the cuttings in containers filled with potting mix. Make sure the containers drain well so the cuttings do not get waterlogged. Check soil moisture every few weeks and water just enough to keep slightly moist.

Sink pots in the ground

Bury plastic nursery pots with the cuttings in a protected spot in your garden. Cover with soil leaving just the top rim exposed. The surrounding earth keeps the roots cooler than being above ground. Mulch over the pots for extra insulation.

Caring for Hydrangea Cuttings Over Winter

Proper overwintering care is vital for the cuttings’ survival. Here are some tips:

• Avoid locations that will have large fluctuations in temperatures like an unheated garage. Consistent cool temps in the 33-40°F range are best.

• Prevent the cuttings from drying out completely but also avoid overly wet soil during the winter months.

• Check on them periodically over winter. Look for any signs of mold, rotting, or pest damage.

• Keep them in partial sun or bright shade so if they start growing early in warm spells, they will not scorch.

• In late winter, move to cooler area if they start leafing out too early. This will help them avoid frost damage.

• If kept indoors, introduce them to sunlight in early spring before planting to harden off.

• Transplant into the garden after the last frost when daytime temperatures are in the 60s.

Troubleshooting Overwintered Hydrangea Cuttings

Even with proper care, you may encounter some problems with your overwintered cuttings:

• Rotting stems: This is caused by too much moisture. Avoid overwatering and use a very well-draining soil medium. Discard any rotten cuttings to prevent spreading decay.

• Dried out cuttings: If the cutting stems are shriveled, they are too dry. Increase watering frequency. Soak the pots to rehydrate.

• No new growth: Some cuttings simply will not make it through winter. Take plenty of cuttings to allow for some attrition.

• Leggy growth: If the cuttings get too warm, they may put out lanky growth. Move to a cooler area before transplanting.

• Leaf scorch: Moving cuttings into direct sun before they are hardened off can burn the leaves. Introduce them to sun gradually.

Paying close attention and making adjustments will allow you to overwinter hydrangea cuttings successfully. With the right care, most cuttings will root and be ready for the garden when spring rolls around again.

Overwintering Tips By Hydrangea Type

There are a few main types of hydrangeas that require slightly different overwintering care:

Bigleaf hydrangeas – These are the traditional mophead and lacecap types (Hydrangea macrophylla). They produce flowers on old wood so protecting the stems is vital. Burying or cold framing is best. Prune only after flowering.

Smooth hydrangeas – These produce flowers on new wood (Hydrangea arborescens). They are very hardy. No need to mulch or bury in winter. Just be sure to leave old stems intact until spring.

Panicle hydrangeas – These hardy types (Hydrangea paniculata) flower on new wood. Leave them exposed over winter and prune in spring. Oakleaf hydrangea is in this group.

Climbing hydrangeas – These vine types need some protection as they are late to go dormant. Mulch well if left outside. An unheated garage is ideal. Limit pruning.

Following the overwintering guidelines for each specific type of hydrangea will give you the highest success rate for rooting cuttings. With proper care, you’ll have beautiful hydrangea plants to showcase in your garden for years to come.