How to Overwinter Boston Fern (Complete Guide)

Don’t throw out that gorgeous, shrubby Boston fern because you can save it for next season. And the season after that. And that.

Sadly, a lot of newbie gardeners still toss out their ferns every winter because they die back and they think that that’s the end.

In other words, they treat them as annuals when they’re actually perennials, friend.

Ferns are awesome for decorating your patio, porch, or even as hanging basket plants. They do well in shade and don’t require a ton of maintenance either.

This is why they’ve become so popular for beginners because they’re really easy to care for. It’s just that when winter comes and they start turning color, people panic and toss them out!

What a waste.

But now, you’ll know exactly how to winterize Boston ferns so you can regrow them again next year.

They’re super easy to overwinter. Even if you’ve never done it before, you’ll be able to follow the steps in this guide with no sweat.

(Because there’s no sweat in the wintertime!)

What is the lowest temperature ferns can handle?

Boston ferns aren’t like most ferns.

They don’t tolerate the cold all too well. Some ferns can handle temperature dips to the extremes (-45F), but Boston ferns are the opposite.

If temperatures drop down to 40F or so, that’s the limit. It needs to be winterized by bringing it indoors, protected with a greenhouse, or possibly mulched.

The absolute lowest temperature is 40F. Any lower and you’ll have a Boston fern that just can’t stand the cold.

Can Boston fern survive winter indoors?

Taking your fern inside your house is one of the most popular ways to overwinter your Boston.

If you have somewhere that’s warm, dark, and free of excess moisture, that’s a suitable home to winterize it.

Your garage, living room, or cellar are good choices. It can’t be completely dark, but it does need some degree of light. Indirect, filtered light is ideal for it.

Don’t use grow lights or put them next to windows where the light is too powerful.

Can Boston ferns survive a freeze?

No, they can’t. You should never leave your Boston out in the cold. Ever.

Some people may say to let it get exposed to the first few touches of frost to help it go dormant, but this is just playing with fire. If it’s too cold for too long, it’ll wilt.

How to overwinter Boston ferns

Winterizing these gorgeous little ferns involves three main steps: knowing when to start preparing, pruning, and then moving them to a sheltered area.

Let’s go over each of these steps in detail so you’ll know exactly what to do.

When to cut back

Pruning them is the first step you should take to get them ready for winter.

Prune in the fall before the winter cold comes because Boston ferns don’t have a tolerance for the cold.

If you’re growing in the right hardiness zone (10-12), the time to cut them back is usually around October to November.

As for the process to prune, here are some guidelines:

Begin by getting a clean pair of your favorite pruners. Dip them in rubbing alcohol to sterilize them. This way you don’t give your fern’s freshly cut leaves any fungal or plant viruses.

Grab your pruners. Cut back the biggest pieces of foliage. These strands should be easy to cut across. Just fold then cut like a sandwich.

Don’t be afraid to take off several inches. It’ll grow back. The more you leave, the more risk you’re taking on for plant diseases or pests to come to eat the dead leaves in the winter.

After you’ve tried it back, remove any leftover clippings that may have fallen into the plant.

If you’re growing in a container, you can hold the plant securely in place then flip it upside down to shake it. This only works for smaller Bostons.

Wash off your plant with a hose to do a further purge of the debris that may be stuck on it. Check thoroughly for leftover foliage. These are insect bait.

That’s it for the pruning. By the time you’re done, your fern should have a few inches of leaves left.

You don’t need to cut it back completely so you get a head start for next season.

But you also shouldn’t be scared of using your pruners to give it a haircut. After all, if your Boston fern is huge, it needs to be cut back to be brought into your house for the winter. If it’s unwieldy, that’s no good.

Note that the type of Boston fern you’re growing may call for a slightly different pruning technique.

But it should relatively be similar to the above steps!

Bringing it inside

Choosing a location for your Boston fern is key.

You probably want to put it somewhere that you can see daily so you can monitor or continue to see your plant daily. Fern lovers would agree to that.

The right location for overwintering your Boston fern:

• Should be cool
• Free of drafts
• Little to no light
• Away from pets
• Not touching walls or other objects
• Preferably on tile

The temperature should be around 50-60F.

Boston ferns don’t need light during the winter. If you keep it near a window, make sure it’s filtered because it’ll burn your plant leaves.

Keep them away from southern facing windows, or any source of light. Your ambient light is enough for them. Boston ferns are shade-loving plants!

The artificial light from your house should be enough.

But continue to monitor for stress. You may need to supplement with some light if it’s been especially dark lately.

Watering

During the winter, ferns need minimal watering. It should only be watered when the top 1” of soil is dry. Don’t overwater.

This only brings in bugs, mildew, or fungus. Aim for watering once a week only.

Plant food

No fertilizer or plant food is needed during the winter.

Remember that it’s not growing during this time so no need to feed it food or else you’ll just bring insects to your Boston.

It’s basically dormant and won’t need food until the springtime when it’s ready to grow those precious greens for you once again.

Pruning

During the winter, your Boston fern won’t look that good.

It’ll be brown, yellow, drooping, or just plain unhappy. It’s OK for it to wilt. After all, it doesn’t have any sunlight or plant food like this used to.

Without these crucial elements, it can’t produce as beautiful greens as it can in peak summer.

Get it?

Prune off the ugly leaves and let it continue to do its thing. It also helps stop bugs from coming to eat them especially if you’re putting them inside your house.

You don’t want bugs to get all over your kitchen! No sir.

When to bring your Boston ferns back out

The plant will be resting during the winter and will be ready to grow when the spring comes.

When temperatures start to rise again and all signs of frost are 100% gone, then it’s time to slowly harden it off to the great outdoors.

Bring it out for a few hours each day over the course of a week.

Then you can return it back to its normal home in your garden, patio, etc.

It’ll regenerate that foliage slowly over time. Resume fertilizing, watering, and typical photoperiods during this time.

It’s normal for it to shed off those yellow or brown leaves from the winter. It’ll replace them with dark green leaves during the peak of summertime.

How do I protect my Boston ferns from frost?

If you can’t bring it to a sheltered place during the winter, there are some things you can do to try to keep it warm outside in your garden.

This is for people that planted their ferns directly into the soil or in planters that are just too big to move.

Keeping your Boston fern full of vitality in the winter is hard if you’re growing it outdoors permanently.

If you can bring it in, do it. If not, it gets tricky.

Here are some things you can do to keep it warm in the garden:

• Build a miniature DIY cold frame
• Use plant covers
• Mulch the roots with 2-3 inches of thick organic mulch
• Use a greenhouse
• Use row covers
• Use heaters
• Build a miniature shelter with stakes, tarp, and tape, DIY style

If you’re in a warmer hardiness zone, then it may be possible to leave your fern outside during the winter. People in zones 10 or higher may be able to do this because their winters aren’t scary.

But if you’re in a lower zone where it dips below 50F, you may have some trouble trying to keep your fern outside in the winter. It’s too cold for it.

Can you overwinter Boston fern in garage?

Your garage is a perfect place to put your fern for the winter.

Why? It’s warm, dark, and dry. This is exactly what the Boston fern wants.

Other than minimal lighting coming in from the garage for a few hours per day, that’s it. Give it some water once a week and you’re all set.

Of course, you should continue to prune it because it’ll wilt its leaves over time. These are food for bugs, so don’t let them destroy your fern.

Continue to watch for any signs of rot or fungus while you keep it there.

If your garage has no light because it doesn’t have those window slits in there, then you can put some artificial lighting temporarily.

This should do the trick. It doesn’t need to be strong lighting- just a few hours per day of daylight spectrum should do it. 6500K blue light is enough.

How to make a Boston fern go dormant

Your Boston fern will go dormant on its own when you winterize it. When the temperatures dip to the 50s ambiently, the fern will stop growing and enter winter dormancy.

During dormancy, don’t water as much, stop feeding plant food, and cut back on the lighting.

When to bring Boston ferns inside

Bring your Boston fern indoors at the first sign of winter.

Depending on your hardiness zone, this is usually in late autumn to early winter.

Check for the first frost date and bring it in before then. Watch out for cold spikes that may occur before the first sign of frost by checking your weather forecast.

Will Boston ferns grow back after winter?

If you overwinter them correctly, there’s no reason why they wouldn’t. Boston ferns are perennials, so they’re programmed to regrow every spring.

However, if your fern doesn’t look like it’s coming back, it may be because of these reasons:

• It was exposed to the cold for far too long
• The first few frosts killed it
• It was infected with a mold or fungal virus
• It was improperly cared for during storage
• Some plant vector got into it during the process
• It suffered plant shock from moving it around
• It wasn’t properly hardened off
• It wasn’t properly potted
• It wasn’t sufficient watered in storage

Boston ferns are pretty hardy by nature, but don’t tolerate the cold for extended periods.

Will my Boston fern come back?

Boston ferns are perennial, so it should come back next year if it was overwintered correctly.

With the new powerful knowledge you gained from reading this guide, you should have everything you need to know to keep it going!

When to put ferns back outside

When you put your ferns back outside when the frost is gone, be sure to slowly acclimate them.

After that, consider upgrading their pot if they’ve grown too big for it.

It’s the perfect time for them to be moved to a bigger planter so their precious roots can grow for the new season.

Opt for the fern to be ⅓ the size of its container.

Splitting your fern is easy. You just cut it down completely down to 1 or 2 inches at the base.

Since it’s already cut back far enough because you winterized it, it’s a good time to do it.

Then you get a new container, fill it with substrate, then place it in there. Repot using a well-draining soil made for ferns.

If you choose to divide your fern, you should do it now because of the same reasons.

It’s cut already, so if you need to divide it, do it now, friend.

How do you take care of a Boston fern in a hanging basket?

Can hanging ferns survive winter?

Similar to Boston ferns that are in the soil or in containers, hanging ferns need to be taken down and brought inside.

Just because they’re in the air doesn’t mean that they’re immune to the weather.

You’ll need to bring them indoors to a warm, dark area for the winter.

Don’t leave them outside in the cold. They’ll likely be killed from the cold and you’ll need to buy another one in the spring. You can hang it in your garage or somewhere in your house if you can keep it clean/tidy.

Otherwise, take down the hanging baskets, then put them somewhere safe from the elements. It won’t mind being out of the air for one season.

Follow the steps above to winterize your Boston fern- no matter if it’s hanging or not.

Further reading/references

• Boston Fern, Nephrolepis exaltata ‘Bostoniensis’
• Boston Fern Wintering Advice? – Houzz
• Anybody successfully bring a Boston fern in over winter? – Houzz

Now you can save your Boston ferns for next season!

Now that you know all the basics for winterizing your fern, you can enjoy them over and over again without needing to buy a tiny one from the garden center every spring.

Boston ferns are ridiculously easy to overwinter and require barely any work. It’s just picking the right time, pruning, then putting them somewhere warm until next season.

Some water and some light will do. That’s it.

Enjoy those big green leaves when it gets their color back. It’ll perk up when the temperatures pick back up eventually, so enjoy it. You’ve earned it.

Do you have any questions? Did you find this guide somewhat helpful? Write a comment and let me know! If you have any tips on your experiences with overwintering the ferns, let other readers know by leaving a comment.