How to Overwinter Hydrangeas in Pots Without Losing Them

Learning how to overwinter hydrangeas in pots can mean the difference between a beautiful hydrangea returning in spring and opening the container to find a dead plant.

Hydrangeas growing in the ground get a lot of protection from the surrounding soil. A hydrangea growing in a container doesn’t have that same insulation. Cold air can reach the root ball from the top, bottom, and sides of the pot.

That doesn’t mean you have to plant every potted hydrangea in the ground before winter.

With a little preparation, many hydrangeas can stay in containers year after year.

Quick Answer: How Do You Overwinter Hydrangeas in Pots?

To overwinter hydrangeas in pots, protect the roots from repeated freezing, keep the soil from becoming completely dry, and shelter the container from cold winter wind. In mild climates, a large pot beside the house may be enough. In colder areas, move dormant hydrangeas into an unheated garage or shed, or insulate the container outdoors.

The biggest mistake is treating a dormant hydrangea like a houseplant.

It needs winter dormancy. It usually does not need a warm living room.

Why Hydrangeas in Pots Need More Winter Protection

A hydrangea may be completely hardy in your growing zone when planted in the ground and still suffer winter damage when grown in a container.

The problem is the roots.

Soil in the landscape acts like insulation. Container soil has much less protection and can cool and freeze faster.

The University of Georgia Extension explains that container-grown plants experience colder root temperatures than plants growing in the ground and may need additional winter protection.

Illinois Extension gives a similar warning, noting that perennial plants in containers face harsher winter conditions because the roots don’t receive the insulation they would get from surrounding garden soil.

That’s why knowing how to overwinter hydrangeas in pots is especially important if you live where temperatures regularly drop below freezing.

Step 1: Know Which Hydrangea You Have

Before deciding how much protection your hydrangea needs, identify what you’re growing.

Common types include:

• Bigleaf hydrangea (Hydrangea macrophylla)
• Mountain hydrangea (Hydrangea serrata)
• Panicle hydrangea (Hydrangea paniculata)
• Smooth hydrangea (Hydrangea arborescens)
• Oakleaf hydrangea (Hydrangea quercifolia)

They don’t all respond to winter exactly the same way.

Panicle hydrangeas are generally among the more cold-tolerant types. Bigleaf hydrangeas can be more vulnerable to winter damage, especially when you’re trying to protect flower buds growing on last year’s stems.

If you aren’t sure what you have, identifying your hydrangea before winter also prevents another common mistake: pruning off next year’s flowers.

Our guide to old wood vs. new wood hydrangeas explains why that matters before you start cutting anything.

Step 2: Stop Fertilizing Before Winter

When you overwinter hydrangeas in pots, fall isn’t the time to push fresh growth.

New tender stems need time to harden before freezing weather arrives.

Once the growing season begins winding down, let the hydrangea follow its natural cycle.

The leaves will eventually change color, decline, and fall.

That’s normal.

You don’t need to wake the plant back up with fertilizer.

UGA Extension recommends avoiding nitrogen fertilizer as plants move toward dormancy because nitrogen encourages new growth when plants should be preparing for winter.

Save the fertilizer for spring when the plant begins actively growing again.

Step 3: Let Your Potted Hydrangea Go Dormant

Don’t panic when your beautiful potted hydrangea drops all its leaves.

A dormant hydrangea can look pretty rough.

You may be staring at a pot full of sticks by December.

That doesn’t mean it died.

Dormancy is part of the plant’s normal yearly cycle.

Let cooler fall temperatures naturally move the plant toward dormancy instead of bringing it into a warm house while it’s still actively growing.

This is especially important if you plan to overwinter hydrangeas in pots inside a garage, shed, or other protected area.

We have a complete guide to what you should do with hydrangeas in fall that covers several of these seasonal changes.

What Should You Do With Hydrangeas in the Fall?

Step 4: Move the Pot to a Protected Location

Location can make a huge difference.

If you’re overwintering the container outside, move it away from exposed areas where winter wind hits it from every direction.

Good locations can include:

• Beside the house
• Against a protected wall
• In a sheltered corner
• Under a covered porch
• Beside other large containers

A north or northwest winter wind can dry and chill container plants quickly.

UGA Extension recommends using buildings, fences, evergreen plantings, and other windbreaks to reduce winter injury.

Just moving a container twenty feet can sometimes give it a much better winter environment.

Step 5: Use an Unheated Garage in Colder Areas

One of the easiest ways to overwinter hydrangeas in pots in colder climates is an unheated garage or shed.

The key word is unheated.

You aren’t trying to convince the hydrangea that it moved to Florida.

You simply want to protect the root system from the worst winter temperatures.

An attached garage can work particularly well because temperatures may stay considerably warmer than outside while still remaining cold enough for the hydrangea to stay dormant.

Illinois Extension lists unheated garages, sheds, and cool basements among the common options for overwintering hardy plants in containers.

UGA also recommends unheated garages as an option for protecting container-grown woody plants from extreme cold.

Does a Dormant Hydrangea Need Light in the Garage?

If the hydrangea is completely dormant and has lost its leaves, light becomes much less important than when the plant is actively growing.

But don’t move an actively growing leafy hydrangea into a pitch-black garage for months.

Allow the plant to enter dormancy naturally first.

When spring approaches and buds begin swelling or leaves start developing, move the plant back toward normal growing conditions.

Step 6: Insulate Hydrangeas That Stay Outside

Sometimes that container is simply too big to move.

I understand.

Once you fill a big ceramic planter with potting mix and a mature hydrangea, moving it may require equipment—or several friends you’d like to keep.

You can still overwinter hydrangeas in pots outdoors.

Start by grouping containers together in a protected area.

Then insulate around the pots with materials such as:

• Pine straw
• Leaves
• Mulch
• Burlap
• Blankets
• Other insulating material

You’re trying to protect the root zone, not make the top of the shrub look pretty.

UGA Extension recommends grouping outdoor containers together and insulating around them when they can’t be moved inside.

Illinois Extension also recommends grouping pots together, placing them on the ground rather than an exposed deck, and protecting them from prevailing winds.

Bigger Pots Are Better for Overwintering Hydrangeas

Container size matters more than many gardeners realize.

A small pot can freeze much faster than a large container containing a big mass of soil.

That’s one reason we prefer generous containers for hydrangeas anyway.

Large containers:

• Hold moisture longer
• Give roots more room
• Buffer temperature changes better
• Dry out more slowly
• Provide more insulation during winter

If you’re planning to keep a hydrangea in a pot for several years, don’t start with a tiny decorative container.

Our guide to the best hydrangeas for pots also covers container size, soil, watering, and compact hydrangea varieties that work well in smaller spaces.

Step 7: Don’t Let the Pot Completely Dry Out

This one is easy to forget.

Your hydrangea isn’t actively growing during winter, so it won’t use water nearly as quickly as it does in July.

But the roots are still alive.

When you overwinter hydrangeas in pots, check the soil occasionally throughout winter.

You don’t want soggy soil.

You also don’t want the root ball sitting bone-dry for weeks.

Illinois Extension recommends maintaining moisture in overwintering containers because dormant roots can continue taking up some water.

If the soil feels slightly moist, leave it alone.

If it has become very dry, give it some water.

This is definitely not the time for a daily watering schedule.

Step 8: Make Sure the Pot Drains

Winter protection doesn’t mean keeping the pot soaking wet.

Hydrangeas like moisture, but their roots still need oxygen.

Make sure the drainage holes aren’t blocked.

A pot sitting full of cold water is asking for root problems.

If the container sits directly on a surface where drainage holes can become blocked, raise it slightly so excess water can escape.

And be careful with decorative saucers.

They’re handy during summer, but you don’t want water repeatedly freezing around the bottom of the container all winter.

Should You Water a Potted Hydrangea Before a Freeze?

Check the soil first.

If the root ball is dry and a hard freeze is coming, watering ahead of the cold can be helpful.

UGA Extension advises checking soil moisture before freezing weather because drought-stressed plants can be more vulnerable to cold injury.

That doesn’t mean flooding the pot right before every freeze.

If the soil is already moist, you don’t need to add more water.

Should You Cover a Potted Hydrangea During a Freeze?

Sometimes.

A covering can help protect stems and flower buds during unusually cold weather, especially on bigleaf hydrangeas.

UGA Extension specifically notes that bigleaf hydrangeas can experience winter and late-spring bud damage and recommends protection during freezing temperatures when needed.

Use something breathable such as:

• Frost cloth
• An old sheet
• A lightweight blanket
• Burlap

When possible, support the material so heavy fabric isn’t crushing the branches.

And remember that wrapping only the top of the plant doesn’t fully protect a container hydrangea.

The roots need protection too.

Don’t Move Dormant Hydrangeas Into a Heated House

This is one of the most important things to understand when learning how to overwinter hydrangeas in pots.

A heated living room generally isn’t the best place for a hardy outdoor hydrangea all winter.

Warm temperatures can interrupt dormancy and encourage the plant to start growing at the wrong time.

UGA Extension specifically advises against keeping hardy container plants in a heated structure throughout winter because they need the seasonal cold period for normal growth and flowering.

A cool garage is completely different from a 72-degree living room.

We want protection from extreme cold.

We don’t want spring in January.

Should You Prune Potted Hydrangeas Before Winter?

Usually, no.

Especially if you don’t know which hydrangea you have.

Old wood means growth that has been on the plant since the last growing season.

Many bigleaf hydrangeas begin forming the buds for next year’s flowers during late summer and fall.

If you cut those stems down before winter, you may be removing the exact buds you’re trying to protect.

Panicle and smooth hydrangeas bloom differently, but there’s still usually no need to rush out and prune just because winter is coming.

Leave healthy stems alone unless you have a specific reason to remove them.

How to Overwinter Hydrangeas in Pots in Georgia

Here in Georgia, our situation is different from somebody growing a container hydrangea in Minnesota or Wisconsin.

Around our area in Zone 7b/8a, we don’t normally have months of deeply frozen ground.

What we do get are temperature swings.

It may feel like spring one afternoon and drop well below freezing a short time later.

For many hardy container hydrangeas here, I’d start with a sheltered outdoor location beside the house.

For a stronger freeze, especially with a smaller pot or a bigleaf hydrangea, moving the container temporarily into an unheated garage offers additional protection.

UGA Extension notes that container-grown bigleaf hydrangeas have the advantage of being movable during cold weather.

The colder your winter, the more protection the roots will need.

How to Overwinter Hydrangeas in Pots in Colder Zones

If you live farther north, I would be much more cautious about leaving an exposed container outside all winter.

A hydrangea that is hardy in your landscape may still lose its roots when they’re sitting above ground in a frozen pot.

Illinois Extension offers a useful general rule for outdoor container plants: choose plants hardy roughly two zones colder than your actual growing zone when you expect them to remain outdoors in pots.

That doesn’t mean every hydrangea will follow a perfect two-zone formula.

Container size, variety, exposure, snow cover, wind, moisture, and the severity of the winter all matter.

But it shows just how different a container is from planting directly in the ground.

In colder climates, an unheated garage or similarly protected location is often the safer option.

Can You Bury the Pot for Winter?

Yes.

If you have garden space available, sinking the container into the ground can give the roots some of the insulation they’ve been missing.

You can bury the pot so the container is surrounded by soil and then mulch around the top.

Illinois Extension lists burying containers in the ground as another method of taking advantage of the earth’s natural insulation.

It may not be the easiest option, but it can work well for gardeners who want to keep the hydrangea in its pot.

When Should You Bring Potted Hydrangeas Back Out?

Don’t rush.

A warm February afternoon doesn’t mean winter is finished.

If your hydrangea has been protected in an unheated garage, watch both the plant and your local forecast.

As spring approaches, you may notice buds beginning to swell.

Gradually move the container back outdoors when severe cold becomes less likely.

If another hard freeze is forecast after new leaves emerge, protect the plant again.

Tender new spring growth can be damaged even on a hydrangea that handled the entire winter perfectly well.

What If the Hydrangea Looks Dead in Spring?

Give it some time.

Hydrangeas don’t all wake up on the same schedule.

Scratch a tiny section of bark with your fingernail.

If you see green tissue underneath, that part of the stem is alive.

Look closely for swelling buds along the stems and new growth beginning near the base.

Don’t cut the entire plant down simply because it hasn’t leafed out as quickly as something else in your yard.

This is especially important with old-wood hydrangeas because healthy stems may still contain flower buds.

The Biggest Mistakes When You Overwinter Hydrangeas in Pots

Most winter problems come back to a few simple mistakes:

• Leaving a small container completely exposed
• Letting the root ball become bone dry
• Keeping the soil constantly soggy
• Fertilizing late and encouraging tender growth
• Bringing a dormant hydrangea into a heated house
• Pruning before identifying the hydrangea
• Forgetting that roots are less protected in a pot
• Moving the plant outside too early in spring

None of this has to be complicated.

Your main job is protecting the roots while allowing the plant to remain dormant.

Our Simple Way to Overwinter Hydrangeas in Pots

If this were one of our hydrangeas, we’d start by looking at three things:

What type of hydrangea is it?

How cold is our winter expected to get?

How large is the container?

Here in Georgia, a large hardy hydrangea in a protected container may need very little attention most of the winter.

A small container with a bigleaf hydrangea deserves more protection.

And if we were gardening several zones farther north, that same plant might spend winter dormant in an unheated garage.

There isn’t one rule that works everywhere.

That’s why location matters so much when someone asks us how to overwinter hydrangeas in pots.

Frequently Asked Questions

Can Hydrangeas Survive Winter in Pots?

Yes. Many hydrangeas can survive winter in containers when their roots are protected from extreme cold and the soil is kept from becoming completely dry.

Can I Leave My Potted Hydrangea Outside All Winter?

Possibly.

Your climate, hydrangea type, container size, and location all matter. In mild climates, a sheltered location may be enough. In colder climates, an unheated garage, buried container, or heavy insulation may be safer.

Can I Put My Potted Hydrangea in the Garage for Winter?

Yes. An unheated garage is one of the easiest ways to overwinter hydrangeas in pots in colder areas.

Allow the hydrangea to become dormant first, and check the soil occasionally throughout winter.

How Often Should I Water a Hydrangea in the Garage?

There isn’t a fixed schedule.

Check the pot occasionally and water when the root ball is becoming quite dry. Dormant hydrangeas use much less water than actively growing plants.

Should I Remove the Leaves Before Winter?

No.

Let the plant drop its leaves naturally.

You can clean fallen leaves out of the container afterward, especially if they show signs of disease.

Should I Cut My Hydrangea Back Before Putting It in the Garage?

Not automatically.

Identify your hydrangea first. Cutting back an old-wood hydrangea can remove next year’s flower buds.

What Temperature Is Too Cold for a Potted Hydrangea?

There isn’t one temperature that applies to every hydrangea.

Variety, root hardiness, pot size, exposure, and duration of the cold all affect how much damage may occur. Container roots experience colder conditions than roots planted in the ground, so give potted plants extra protection during unusually severe cold.

Final Thoughts on How to Overwinter Hydrangeas in Pots

Once you understand what you’re protecting, learning how to overwinter hydrangeas in pots becomes pretty simple.

Protect the roots.

Let the plant go dormant.

Don’t overwater it.

Don’t let it dry out completely.

Keep it out of harsh winter wind.

And don’t bring it into a warm house thinking you’re doing it a favor.

Your exact method will depend on where you live. Here in Georgia, shelter and occasional freeze protection may be enough for many container hydrangeas. Farther north, an unheated garage or similar protected location makes much more sense.

Take care of those roots during winter, and there’s a good chance that pot full of bare sticks will surprise you with fresh green growth when spring returns.

For more real-world hydrangea and flowering shrub help, follow Bobby & Lynn’s Plant Farm on Facebook. We share what we’re growing, what works for us, and the gardening problems we run into along the way.