How to Overwinter Hydrangeas in Pots: A Complete Guide

Hydrangeas are one of the UK’s favourite blooms. If not the favourite. They are often grown in flower beds or pots because they can handle both conditions. The flowers are big and round, which makes them very attractive. Also, now that it’s fall, you should start thinking about putting hydrangeas in pots to stay alive all winter.

Taking all the necessary steps to make sure your plant survives the winter is what overwintering means. These steps vary from plant to plant.

If you know how to grow hydrangeas in pots and already have a plant in a pot, here’s what gardening experts say you should do to keep it alive during the winter.

Hydrangeas are stunning garden plants that also make beautiful container specimens. Their large mophead or lacecap flowers add elegance to outdoor living spaces. While hardy in the ground in many regions, potted hydrangeas require special winter care in colder climates. Properly overwintering your container hydrangeas will allow you to enjoy these shrubs for years to come.

Getting Hydrangeas Ready for Winter

Preparing hydrangeas for winter dormancy starts with proper fall care:

Reduce watering Slowly cut back on watering as temperatures cool and growth slows. Aim to keep soil slightly moist, not saturated
Apply fertilizer Give pots a final feeding in early fall with a balanced organic fertilizer This fuels energy reserves to survive winter

Protect from frost Move pots to a sheltered area once nighttime temperatures drop into the 30s or 40s F. A porch or covered patio works well.
Remove dead leaves/flowers: Prune off spent blooms and yellowed foliage to prevent disease issues. Leave any healthy leaves in place for photosynthesis as long as possible.
Check soil moisture: Feel the soil before winter arrives. Water any pots that feel dry so roots don’t desiccate over winter.

Getting pots ready before cold weather allows plants to harden off and enter dormancy stress-free.

Ideal Winter Conditions for Container Hydrangeas

Hydrangeas in pots thrive over winter in an unheated, protected location with:

Temperatures between 32-55°F.

Low light.
High humidity.
Minimal watering.

Protection from severe cold and wind.

A cool corner of a garage or basement often provides these conditions. Choose the coolest spot available for best results.

Good Spots to Overwinter Potted Hydrangeas

Here are suitable areas to store dormant hydrangeas for winter:

Unheated garage or shed: Place pots away from sunny windows on the concrete floor or shelves. Move outside once daytime temperatures are consistently above freezing.
Basement: An unfinished basement with concrete or dirt floors maintains cool, humid conditions.
Crawl space: Like a cool basement without the stairs. Provide minimal water.

Insulated storage box: Place dormant pots in a sturdy plastic box filled with bark, leaves, or straw for insulation. Store in a cool area.
Cool porch: Enclose or insulate pots to protect from intense winter sun and wind. Remove wrap in spring as growth resumes.
Outdoor trench: Sink pots in a trench lined with straw or leaves. Cover tops with soil and mulch.

Preparing and Caring for Overwintered Pots

Follow these tips for successfully overwintering container hydrangeas:

Select a durable overwintering pot that won’t crack in freezing weather. Sturdy plastic works better than thin ceramics.

Check soil moisture monthly and water sparingly to keep from totally drying out.
Insulate above-ground pots by surrounding with bark, leaves, straw or other organic mulch.
Move pots to a sheltered, shaded spot once temperatures warm in spring.

Remove insulation, prune any dead growth, and begin regular watering as new growth appears.
Feed with compost tea or organic fertilizer to replenish nutrients after dormancy.

With proper care, container hydrangeas can survive tough winters and re-leaf beautifully come springtime. A little effort goes a long way to enjoying these elegant plants for years.

When to start overwintering hydrangeas in pots (Image credit: Getty Images/Konstantin Aksenov)

Similar to overwintering petunias, it’s very important to get the timing of bringing in your potted hydrangeas right.

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‘You should start overwintering potted hydrangeas when the temperatures drop and before the first frosts,’ Fiona advises.

Steve gives a more specific advice about when to start the process: “I suggest starting the overwintering process in late fall, around October or November time.” ’ So it’s about time.

Over-Wintering Potted Hydrangeas

FAQ

Can hydrangeas survive winter in pots?

Potted hydrangeas overwinter best in a garage or basement where the temperature stays cool but doesn’t freeze. The plants will go dormant, but you’ll still need to water the pots occasionally, about once a month, to keep the roots moist, until spring.

Can I leave my potted hydrangea outside?

Overwintering Potted Hydrangeas It is best to leave them outdoors so that they are exposed to the seasonal changes; however, they may need some protection from wind or deep freezes.

Do potted hydrangeas come back every year?

As rapid growers—averaging about 2 feet of growth per year—larger varieties of hydrangeas can reach up to 15 feet tall. Applicable in growing zones 3 to 9, hydrangeas are a low-maintenance plant that, with proper care, will return year after year.

Should I cut down my hydrangea for winter in the fall?

Prune back stems to just above a fat bud — called a heading cut — in fall, late winter or spring. These plants have conical-shaped flower heads. I recommend leaving the dry, tan flower heads on the plant to provide some winter interest in your landscape, so I wait to prune these until late winter or spring.

Should I care for my potted Hydrangea over winter?

Properly caring for your potted hydrangea over winter will determine how successful the blooms are in the following summer, and how many you get. The key to this is to protect your plants against the first frost of winter.

Can hydrangeas overwinter?

Make sure your container will withstand the rigors of winter. If not you may want to move the plants to a nursery pot that can be placed inside the decorative pot during the growing season. Overwintering these types of hydrangeas indoors is difficult and usually not successful. Here are a few ways to overwinter your plants.

Can you leave a potted Hydrangea outside?

Leave the plant outside If you take a number of precautions, you can leave your potted hydrangea outside in the garden. ‘You can move them to a sheltered spot in your garden and raise the pots off the ground using pot feet or bricks,’ advises Fiona.

Can hydrangeas survive winter?

Continue watering until the ground freezes. Make sure your container will withstand the rigors of winter. If not you may want to move the plants to a nursery pot that can be placed inside the decorative pot during the growing season. Overwintering these types of hydrangeas indoors is difficult and usually not successful.