How to Overwinter Agapanthus Plants (Beginner’s Guide)

Agapanthus is known for its big blooms, thick roots, and dazzling colors.

This plant is hardy by nature so it has plenty of tolerance for the winter.

When grown in zones 9-11, agapanthus doesn’t need much additional care for the cold weather.

But if you’re in a lower zone, you’ll have to give a bit more TLC to care for it during the winter.

Agapanthus can be both deciduous or evergreen, depending on the species you’re growing.

They’re native to South Africa, but they can thrive in the colder regions with a bit of help from you.

You can do a little like mulching or using a cold frame.

Or you can do a lot like lifting their bulbs to store in a temperature-safe environment (like indoors).

Similar to most bulbous plants, they can be safely put into a cozy box filled with substrate for winter storage.

Let’s go over the different things you can do to overwinter and care for your agapanthus during the cold season!

Last updated: 10/27/21.

Can agapanthus be left outside in winter?

It depends on the type of agapanthus you’re growing.

  • Evergreen varieties are less tolerant to the cold, therefore should be suited for USDA zones 8 or higher.
  • Deciduous varieties are more cold-hardy and will tolerate temperatures all the way down to zone 5 or so.

If you don’t know your zone, find out.

Even if you’re in the “right” zone, note that extended periods of cold will kill your plants.

They can handle temp dips as low as -10F or so, but if it dips lower or remains that way, then your plant is at risk.

Being part of the amaryllis family, they’re used to colder weather. So that’s good.

Perhaps you’re in a colder region, and you’re wondering how your agapanthus is going to go down when the storm comes.

It’s pretty scary if you’ve “grown” on your plants!

What happens to agapanthus during the cold season?

It’s one of two things, depending on the variety:

Deciduous agapanthus will simply die back on their own. The rhizomes are shielded from the cold under the soil line, so it doesn’t get killed by the cold.

These are less work compared to evergreen species and you don’t need to do as much work for these plants.

Evergreen agapanthus will keep their foliage out during the winter time, as they’re bright and showy.

This will make them vulnerable to the cold and will require you to make some adjustments to protect them.

The hard way to tell the difference between the two is by lifting the bulb. The easy way? Just check the leaves when the winter comes.

Are they starting to wilt and fade because of the cold?

If so, then you’re likely growing a deciduous plant.

If they seem to ignore the cold and keep their color throughout the winter, then it’s probably evergreen.

Evergreens are the ones you need to watch out for. If you leave it out, then it’ll be harmed by the cold. Time to get to work.

How to overwinter agapanthus

Overwintering agapanthus.
Overwintering agapanthus isn’t scary!

This depends on the type of agapanthus variety you’re growing.

It also heavily depends on the local conditions during the winter time. If you’re not sure what type you have, you need to find out.

If the plant is evergreen, then you’ll need to give it some extra care for the wintertime.

Finding out if it’s deciduous or evergreen is easy. You can do it by inspecting the tubers before winter arrives.

Or simply look at the foliage when the cold is here- if it’s still bright, showy, and full of leaves, then it’s likely a deciduous.

If you’re in a warmer zone

For those in a higher zone where the winters are mild, you pretty much don’t need to do anything.

This hardy plant will tolerate the mild cold without a problem. Just leave it alone during the winter!

But, you do need to cut it back before the winter comes.

Cutting back the foliage will allow it to hibernate during the winter time.

It also stops bugs from eating the dead leaves. Cut back your agapanthus to just the bare stem.

Cover the exposed stem with a layer of organic mulch to at least 2 inches. Mark the area so you don’t trample it.

When the spring comes, remove the mulch and allow the plant to regrow.

If you’re growing evergreen agapanthus, give it a bit of water here and there during the winter.

If the region you’re in tends to be dry, it’ll need some water to drink. Use your finger to feel the top 1” of soil.

It should be barely wet, but never completely dry. Don’t fertilize during the wintertime until spring comes.

You can then begin watering and feeding like usual.

Easy, right?

Wintering evergreen agapanthus

Evergreens will need extra care. It’ll need to be cut back in the summertime as soon as fall approaches.

Do NOT wait until the cold comes.

It’s just an unnecessary risk to take, especially when grown in northern regions where it gets really cold.

The plant needs to be cut back at the end of summer or early fall right before the cold begins.

Check your forecast and look up your frost dates.

Upon cutting back, you’ll then dig up the roots next.

The tubers should be cleaned.

Use a soft-bristle toothbrush to gently brush off soil that’s stuck on them. Let them dry out after you clean them.

The roots will likely have all sorts of dirty clumps stuck on them plus the moisture from prior waterings.

Keep them somewhere dry, warm, and humid-free. You can wrap them in some paper while they dry out.

Keep the light in the room minimal during this time.

Store in a dark, dry, light-free environment. Aim for temperatures between 40-45F.

When the spring comes, check for mold, fungus, or spores. If you see any, dispose of the bulb because it’ll be useless.

If everything’s good to go, then you’re ready to plant them again for the season.

Evergreens are difficult to overwinter compared to deciduous.

If you’re in zones 6-8, you’ll have a tough time getting them to stay outside during the cold.

Zones that stay above 60F should be OK leaving them in the soil throughout the winter, but they also need full sun.

So if the sun goes away with those shorter days, it’ll suffer.

But if temps are good, plus the sun is bright, you may get away doing nothing. Just water it once a week.

Don’t let it go dry.

If temperatures fluctuate around that threshold, add some mulch. 2-3 inches of organic mulch around the root to help keep it nice and warm.

Mini greenhouses, cold frames, or plant heaters are also good choices.

Smaller agapanthus plants can be covered with a portable greenhouse, without disturbing the plant.

Lastly, you can move your agapanthus into a container.

If you set up a temporary housing area that has temperatures around 60F with 12 hours of sunlight per day, then you can keep your evergreen going through the winter.

Use a grow light for plants if you don’t have the sunlight to give it. When the spring comes, move it back to the original location.

This is to be used as a last resort. It’s not good for the plant to constantly move it. So avoid doing so if possible.

One handy tip is to use containers to grow your evergreen agapanthus.

This makes it a lot more convenient because you can simply move the container when the cold comes.

You also don’t need to uproot it and mess with the roots each time the cold comes. The pot can be brought inside your house when the winter comes.

This saves you a ton of time plus reduces plant shock.

Be sure to provide some light by placing agapanthus next to a window in your house.

Don’t fertilize during this time, but continue to water at a reduced rate.

Wintering deciduous agapanthus

Deciduous variants will need to be cut back.

When it turns yellow, cut it back, but not too early.

It should start to die back on its own. When the leaves start to wilt and change color, then it’s time to cut.

If you do it before it will, it won’t have enough energy stored for the winter.

As you can see, deciduous agapanthus is a lot easier to overwinter vs. evergreens.

If you’re in zones 8 or higher, then you should be OK following this plan of care.

If temperatures remain between 40-50F degrees or so, then you don’t need to do anything else.

The leaves will have stored energy for the next season stored in their rhizomes.

This is why it’s important to wait until the leaves have turned color before you cut it back to a few inches from the soil line.

Without any leaves, it can’t generate any energy during the winter. Therefore, light doesn’t matter.

Whether it’s completely dark or bright, the plant doesn’t care. It can’t photosynthesize anyway.

However, just water it once every 2 weeks or so. This will prevent it from going completely dry, which you don’t want.

If you’re in a lower zone, such as 7 or lower, then add some mulch to it.

2-3 inches is good enough. It’ll shield it from the cold by insulating the temperature swings at night time.

If temperatures remain above 40F, then you’re OK.

If it dips further, your plant may be in trouble.

You may have to add extra mulch. You can use bark or straw as a substitute if you don’t have mulch.

You can also lift the rhizomes and then put them in the newspaper.

Clean the roots, dry them, then wrap them loosely.

Get a box and fill it with sawdust. Then gently place the rhizomes in there individually.

You can add something like sulfur to help prevent any fungal issues during storage.

Don’t let the rhizomes touch each other. Put the box somewhere around 45F. Keep it cold, dark, and dry.

There’s no need to add water.

The easiest solution?

Growing agapanthus in pots! All you need to do is move the container inside your house and you’re set!

Not literally inside, but somewhere that still has cold exposure, like your deck. Agapanthus needs to be exposed to cold so it goes dormant in the winter.

If you keep it awake the entire time, it will produce small blooms next spring. Temperatures around 45F should be enough to simulate the dormancy threshold.

When the spring comes and the last frost is over, then you can move it back to your garden.

Some people will suggest transplanting the entire plant to a new container. This is possible but is a lot more work than it needs to be.

You buy a new container and then move the plant to the new pot.

The new temperature location needs drainage.

You sit in there for the winter until spring comes. Then you move it back out.

Agapanthus doesn’t like to be moved around, so that’s why I don’t like this way of doing things. It can affect the bloom quality.

Other common questions about winter care for agapanthus

Here are some commonly asked questions from readers about taking care of these plants during the winter.

Do I cut my agapanthus plant back in winter?

For deciduous varieties, you don’t need to cut them back until after they start to wilt on their own.

Remember, they need to harvest energy from the sunlight with whatever’s left of their leaves.

They store it for the winter inside the rhizome.

So don’t cut them back early. They wilt on their own, so they’ll naturally tell you when they’re ready to be cut back.

Once they’re done, then you can cut them back to 2-3 inches from the soil line. Easy enough

For evergreens, you’ll need to cut them back.

They keep their leaves throughout the winter.

If you don’t plan on moving them to a sheltered place, then you should cut the leaves back because they’ll likely drop them on their own.

See each section for details above.

When should I cut down my agapanthus?

Cut it down when it begins to wilt on its own.

When the leaves turn brown or yellow and drop, then it’s time to cut back if it’s deciduous.

If it’s evergreen, cut it back when the cold is here.

What do you do with potted agapanthus in the winter?

It depends where you live.

You have multiple options:

  • Add 2-3 inches of organic mulch
  • Use a mini greenhouse
  • Use a cold frame
  • Use straw, bark, or leaf litter
  • Move them indoors if grown in pots
  • Store them in cardboard boxes wrapped in newspaper
  • Plant them in pots temporarily somewhere warm

Caring for agapanthus in pots winter care

If you’re growing your agapanthus in containers, congrats, you’ve got it easy.

Just move them somewhere where the temperatures are around 45F throughout the winter.

If you’re growing evergreens in pots:

Give it water when the top inch of soil goes barely dry. Stop all fertilizing. Keep it under a grow light for up to 14 hours per day.

If you’re growing deciduous in pots:

Water once every 2-3 weeks. Stop fertilizing. Keep it in a dark area.

Container growing is cool because you can easily move it around as needed.

If you grow it in a big enough pot, you never need to upgrade it either.

Remember that agapanthus doesn’t like to be uprooted.

How cold of a dip in temperature can agapanthus take?

This varies depending on the variety you’re growing, but they can take cold swings down to -10F on average.

Note that these should not be the typical overnight temperatures.

They can’t sustain themselves when it’s this cold constantly.

But a cold swing here and there is OK.

Further reading/references

Overwinter without worry

Bug eating Lily of the Nile.
Take care of your Lily of the Nile and it’ll reward you with pretty blooms.

Now that you know all the basics of winter care for your agapanthus, you can keep it safely without worry!

Although those growing deciduous agapanthus will have a much easier time, evergreens can continue to produce those pretty leaves during the winter if you’re keeping them awake artificially.

There’s always a bit of a nuance depending on where you’re growing, your local climate, and the type of agapanthus you’re overwintering.

Got questions? Post them below and ask away!

If you have any tips to share with other readers, post them as well.

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