How to Winterize Astilbe Plants (Guide)

So, you need to take care of your astible over the winter.

These gorgeous plants have a lot to offer- even after they’ve changed their color and dropped their flowers.

These “dancing fairies” show off their signature look in the cold season with their bare stems siting in the snow.

Then in the spring, they grow their millions of flowers all season for you to gaze upon.

And they don’t ask for much. But you can learn how to maximize and get the most out of your astilbe over the winter.

Enough talk. Let’s dive in.

General things to know about astilbe care

https://www.youtube.com/watch?v=F8Pw6s2pfuQ

Astilbe is a perennial plant that does well in zones 4-8.

It’s known as a “shade plant” because it thrives in areas with partial or full shade.

Astilbe is a hardy plant that is cold hardy and handles very cold, hard conditions without any problems.

For most people, nothing needs to be done to care for astilbe during the winter.

But for those in a cold hardiness zone, consider the following tips for some wintertime TLC.

What does astilbe look like in winter?

 

Astilbe is known for their unique figure when they’re wilted and only the skeletal branches are leftover in the winter.

These flowering herbaceous perennials will slowly die off as the winter approaches and will lose all their leaves and foliage.

Colder climates force this plant to start fading and losing all their color, leaving only bare brown dry remnants.

Even then, these are considered to be a decorative piece to any fall garden. They don’t look that bad and blend well with other plants that are still flowering during the late fall like pansies.

As the real frost approaches, they’ll die back and shrink down in size.

All that’s left are the thin branches sitting above the snow in a field of powder.

When you have a few of these plants remaining, it adds a touch of that “winter feeling.”

The seeds are still intact and provide a food source for birds and small animals throughout the cold.

Similar to winterberry holly, astilbe attracts a variety of wildlife to your property throughout the winter as they scavenge for remaining food.

How do you winterize astilbe?

Properly taking care of astilbe over the winter is straightforward and easy.

There’s not much to it and generally, most zones won’t have to do any additional work.

These plants are suited for the cold climate and provide texture and decor even when they’re completely wilted and dried out.

Here are some tips to care for them during the cold season.

Cutting back

Cutting your astilbe be back is a necessity no matter your hardiness zone.

This needs to be done before they enter winter dormancy

Use a pair of sharp pruners and clean them beforehand so you clear out any chance of mildew or fungal infestation.

Then, cut each stem down to 3” from the soil level. The cut stems can be used for compost or used in decor pieces in your home.

The best time to cut back is the wintertime. This makes it neater, tidier, and cleaner so you can have an easier time caring for your astilbe in the cold.

Don’t feel bad for cutting down your plant. it’s a necessary step if you want healthier plants next season.

Note that when astilbe is cut back, it’s very easy to accidentally dig up the remaining plant or even step on it.

Use cheap plant markers to alert yourself that the plant still exists and to avoid harming the short stems.

You’d be surprised how many times people have stepped all over their plant without even knowing it!

Deadheading

There’s no need to deadhead this plant in the winter.

Unlike other plants that benefit from deadheading, but astilbe doesn’t.

Leave the foliage and flowers in place throughout the autumn and they’ll wither off on their own by the winter.

If you must, here’s a video demonstrating the process:

Watering during the winter

Although astilbe is dormant in the cold, it still requires a steady watering regimen over the winter.

But it’s important to note that you should never overwater during this time.

The plant requires very little water to sustain itself and any excess water you add can pool and lead to root rot, fungus, or even kill the plant when it gets too cold.

Astilbe does like water, but won’t fare well if the water pools up under the soil.

All you need to do is keep the soil nice and moist. Water 1-2 times per week until the first frost.

Astilbe appreciates plenty of moisture so keeping them hydrated is important.

However, when the first frost comes, cease watering.

You can water occasionally, but rarely, when there is no rain or snow present and the temperatures are above freezing.

Don’t water if the temperatures drop below 40F. This is important if the temperature is noticeably cold and the humidity is very low.

Dry winters will damage the plant’s root system so you need to keep it wet.

Plant tissue that’s well hydrated is protected against damage from the cold.

Add plant food

Fertilizing your astilbe can be beneficial for the plant all season long, not just in the winter.

Use a slow-release tablet or stake that has an NPK rating of 5-10-5 as this plant loves phosphorous.

Fertilize during the spring and again in the fall.

Do it when the temps drop off and avoid fertilizing right before the cold season as you don’t want the plant to continue developing and growing into winter. This is the opposite of stimulating dormancy.

Use and apply as directed. The latest you should add plant food is in the late autumn when the soil is still soft and the temps are still cold.

Mulch plenty

Mulching is key to overwintering the majority of winter plants. And astilbe is no exception.

Similar to dahlia, adding mulch will provide a layer of protection to guard against the frost of the winter. Mulching also has other added benefits like water preservation, helping drainage, and supplying nutrients for the plant to feed on.

You can use high quality, organic substrates like leaf litter, humus, compost, or straw mulch.

Add a 1-2” layer on top of the soil surface during the cold to help safeguard your plant. You should be monitoring the forecast and adding mulch during the cold snaps.

Apply after the soil has frozen if you live somewhere that dips below freezing. Remove the mulch in early spring before new shoots appear in the soil because the mulch will cover it up.

The mulch should be placed around the stem to help regulate the soil temperatures and stop wide swings.

Don’t put it down until the frost. If you mulch during the warmer months, it could cause root rot from the high humidity and warm temps.

Propagate by division

Astilbe that has been growing for many years need to be propagated by dividing up the rhizome.

Typically, they’re ripe for propagation after 3 years. You can safely and carefully uproot the plant by digging around the plan bulb approximately six weeks before the first frost.

Be careful not to damage the rhizome, as it sits right around the 12” mark below the soil. You can use a shovel if you’re handy, but otherwise, a large garden spade will do the trick.

When you see the rhizome sitting there, dig up all the dirt around it, and lift it out.

Be sure to not pull it carefully from the dirt. Try to avoid pulling up the roots when they’re still tangled to the clips of dirt. Tease them apart from the surrounding earth and lift it.

You may have to spend some time doing this depending on the soil consistency, but take your time.

After you dig it up, separate the rhizome into multiple pieces and replant them as desired.

If you messed up earlier and your current location doesn’t provide the best soil acidity, sunlight, or other optimal condition, now’s your chance to relocate the new rhizome to the ideal location.

Astilbe likes phosphorus-rich, acidic soil with plenty of shade and well-draining viscosity.

Plant each rhizome about 30” apart or put them into containers if you want to overwinter the new plants indoors. Transplant outdoors in the spring.

Cutting back improves the appearance of the herbaceous perennial and keep it pest-free from feeding insects.

If you don’t cut it back, the foliage left on the plant will damage the crown from the constant thawing and freezing cycles over the cold season.

This needs to be done before the cold drafts show up to contribute to plant damage.

Build a cold frame

You can build a simple DIY cold frame to help insulate against the elements.

This usually consists of 4 pieces of wood with a cover and can be made for next to nothing.

The cold frame sits over and around the wilted astilbe to keep wildlife out and helps trap in moisture and warmth from the daytime.

There are dozens of designs you can find online and plenty of tutorial videos you can use for step by step directions.

Here’s a sample:

https://www.youtube.com/watch?v=b75RoDmE9qY

If you have a greenhouse, you can safely place your potted astilbe in there to keep them warm, yet give them enough cold exposure during the winter chill to enter dormancy.

Use a greenhouse

A greenhouse can always be a good solution to keep your plants warm and the temperature controlled over the winter. Astilbe does well in a greenhouse with some degree of cold exposure to enter proper dormancy in the winter.

Do nothing

For those in higher hardiness zones, you may be able to get away by doing absolutely nothing!

Milder winters can be sustainable for astilbe, as it is a cold-hardy plant.

Depending on your local climate, monitor the weather forecast, and note any dips in the temperatures.

If you see a cold snap coming, plan ahead and then spring into action before the cold.

Use a blanket of mulch to help protect and insulate the soil.

A simple, 2” layer of organic straw mulch will do the trick.

Overwintering astilbe in pots

Astilbe can be winterized indoors using plant containers.

If you’re growing from new rhizome divisions, take the new plant indoors and store it somewhere cool and dark.

The soil should be a high-quality brand, acidic, and loamy consistency. The temperatures need to be cold enough for the plant to “rest” during this period of dormancy, but not to the point where it kills it.

After the winter has passed, take it back outside and let it acclimate to the spring temperatures over a month or so.

After the plant has established itself outdoors, there’s no need to bring it back in.

Don’t uproot it after it’s built a root system outdoors to overwinter indoors using containers.

The whole idea of overwintering in a pot is for plants from new rhizomes or that have never been transplanted before.

When you move them outside in the springtime, do it slowly. Let them experience the warming temps, humidity, sunlight, and shade.

Start with a sheltered area of your yard, such as next to an exterior wall or microclimate that’s safe from strong winds and rains.

Slowly move them out into the exposed areas (or wherever you plan to plant them permanently) over time. This will help them get used to it safely.

Other FAQs

Here are some other commonly asked questions about astilbe care.

How do you keep astilbe blooming?

Astilbe will naturally wilt in the winter.

This is a normal rest period for perennial plants. it’s beneficial for them, so don’t try to stop them from entering dormancy.

Plants that are grown indoors without a period of dormancy end up having fewer blooms, volume, and color than plants that are naturally given a dormancy time.

Some plants even need a period of “chill exposure” to produce the best leaves possible.

Take good care of them and you’ll have blooms all summer for you to enjoy!

Why did they turn brown?

Astilbe does this on its own. It’ll naturally change to a brown stem and nothing more in the winter.

Think of them like dancing fairies in a field of white snow. This is a signature look that many gardeners appreciate.

Are they annuals or perennials?

Astilbe are perennials.

They bloom in the spring until late autumn and then they’ll naturally turn color and drop all their leaves.

When cared for over the winter, they’ll come back in the spring and bloom again. Cut back for the best blooms next season.

Will astilbe rebloom if deadheaded?

There’s no reason to deadhead astilbe, as it doesn’t do anything to help it produce more flowers.

You should, however, cut back the stems to 3” from the soil surface before the cold.

But the flowers themselves can be left alone to drop off, even if they’ve been spent.

Why isn’t my astilbe blooming?

Astilbe blooms may be lessened or damaged because of changing seasons.

If your plant doesn’t bloom, you can do the following:

• Cut back the stems every winter
• Use an acidic well-draining soil
• Add plenty of fertilizer in the spring and fall, but not winter
• Use a 5-10-5 NPK plant food
• Plant in the shade or partial sun
• Water your plant

Do astilbe bloom more than once?

Yes, this plant is a perennial which comes back every year when properly cared for.

They bloom between spring and summer with gorgeous flower plumes that contain tightly packed tinier flowers.

One opens after the other and they eventually all get their turn. They bloom at different times during the year and this is how they keep going all season.

That’s what makes them one of the few plants that offer an all-season presentation- blooms through spring and fall with thin stems on the snow in winter.

Astilbe is a plant that you can enjoy all year even if it wilts in the cold.

Further reading

Here are some additional references you may find useful:

• I always think this astilbe looks like a forest for fairies – Reddit
• Help for astilbe? : gardening – Reddit
• Astilbe, how well does it grow for you? – Houzz

Now you know how to winterize astilbe

You have everything you need to know about caring for this cold-hardy plant over the winter.

Since it’s a relatively easy plant, there’s not much that needs to be done other than some basic pruning, mulching, and transplanting for the spring.

Otherwise, go ahead and enjoy those gorgeous “dancing fairies” in the field of pure snow out there.

If you have any questions, post them in the comments below. Or if you have any tips you’ve picked for astilbe in the winter, please let me know!