Caring for plants is already tricky as it is. How about when the weather is unbelievably cold, and the rain just can’t seem to stop?
In the winter, plants need extra care to survive the cold season. You need to monitor the temperature to get them inside if needed. Not only that, but you’ll also have to ensure they’re getting enough water.
At the same time, you’ll need to provide a place that receives sunlight, which may be scarce during the cold months.
If you’re wondering about Boston fern winter care, you landed on the right page. Here’s everything you need to know about the matter, from where to put the plant to how to deal with frost.
Boston ferns are originally tropical plants, so they thrive in warm temperatures. They prefer the temperature to be 65 degrees at night and no more than 95 degrees during the day. That means that they don’t like the cold nor react well to scorching temperatures.
They can live in temperatures below 65 degrees, but their growth rate won’t be as good.
A Boston fern thrives in temperatures between 65 and 95 degrees and can tolerate temperatures between 50 and 60 degrees nicely.
When the temperature gets below 50 degrees, the plant starts to struggle, and anything below 40 degrees is a sure death.
A Boston fern can only survive the winter outside if the temperature doesn’t drop below 40 degrees. That’s a slim chance in naturally cold areas, so it’s safe to say that Boston ferns don’t survive the winter outside in most areas.
If the temperature stays between 50 and 55 degrees during the winter, your plant can probably stay alive outside, provided that you care for it well.
However, the best option in all cases is to bring the plant inside.
That’s especially if you live in an area with unpredicted snow storms. Frost can kill the plant if it stays long enough, so avoid these instances by keeping it inside all winter.
Bringing your Boston fern inside for the winter is totally doable, and it’s actually the only proper solution in some cases. Instead of leaving the plant to struggle in the outdoors, it seems legit to bring it inside and provide it with the care it needs.
To start with, look for someplace that gets at least two hours of sunlight per day. You can look for a south-facing window and place the plant close to it.
Then, make sure that the room’s temperature doesn’t go below 55 degrees at night and doesn’t exceed 80 degrees during the day. You’ll need a thermostat to make correct adjustments.
Next, you’ll need to provide the plant with the humidity it needs.
For that, grab a pebble tray and keep the plant pot on top of it. You can also create a spray bottle of distilled water and use it to mist the plant once each week.
If the weather is still too dry for the plant, it may be a good time to invest in a humidifier. Keep in mind that humidity is no joke for Boston ferns. When the air is dry, they become more vulnerable to spider mites and the like.
When the temperature starts going below 50 degrees, it’s a good time to bring the Boston fern inside. The fern can only survive temperatures that low when it’s in a pot, and even then, once the temperature goes below 50 degrees, it’ll start struggling for its life.
So, it’s a good idea to start allowing your plant to go inside when the temperature is around 50 degrees. If you’re expecting frost any time soon, it’s also better to let the plant go dormant.
Before you decide to take the plant inside, there are steps you can take to prepare it for the winter. Here’s a roundup:
- Prune all the old fronds to give space for the newly grown ones and to prevent messy shedding. Leave only the youngest fronds on the plant.
- Instead of moving the plant from outside to inside suddenly, try to give it some time to adapt. Change its location first to stay on the patio, for example, where it’s still outdoors. Then, after a few days, bring it inside.
- Use distilled or filtered water to water the plant throughout the winter.
- Don’t maintain your regular watering schedule. Instead, reduce it to once every two weeks or less, but make sure the soil stays moist without drying out. You can mist the plant every couple of days to make sure it gets enough humidity.
- Keep from fertilizing your Boston fern when moving it indoors, and keep it that way throughout the winter.
- Before storing the plant in the winter, put its pot in a large tub full of water. This will help hydrate the roots before the dormancy period, and it’ll cause any pests living inside to come to the surface.
- After you bring the plant inside, keep it away from any other plants. It’s better to do that so that if it contains any pests, they don’t move to the other plants. It’s essential to treat the issue first.
- During dormancy, keep monitoring the plant to make sure no pests find their way inside the roots. If you find any, look for a suitable treatment as fast as you can to keep the issue from spreading further.
If you don’t want to let your plant into dormancy when you can care for it, you can take some steps to keep it alive. It may stay semi-dormant, a stable state of staying alive but not growing regularly.
To do so, put the plant in a secluded room, setting its temperature to 50–60 degrees. That way, the plant won’t require frequent watering.
Maintain weekly watering schedules, ensuring not to get the soil too wet or soggy. It should stay moist throughout the winter.
If your house is dry, you can get a humidifier for the room. Boston ferns don’t react well to low humidity because of their original living conditions in tropical areas.
Boston ferns typically don’t go dormant in winter. If you provide them with their living requirements, they’ll keep growing, but most people allow them to go dormant anyway.
Letting the plant go dormant is an ideal solution if you don’t have a safe place to keep it. If you live in an area with freezing cold or frequent snowing, you likely won’t be able to keep the plant alive during the winter.
In this case, it’s better to let it go into the ignorant bliss of dormancy.
If you don’t have a suitable place to keep your Boston fern during the winter, you can follow these steps to let it go dormant:
- Check the plant’s fronds and cut them so that they don’t exceed 2 inches on average
- Put the plant in a cool, dark place, such as a garage or a covered garden shed
- Monitor the soil weekly, keeping it slightly moist but not wet
- Use distilled water to mist the plant when needed
- Avoid using any form of fertilizer while the plant is in a dormant state
If you let your Boston ferns go into dormancy during the winter, and now you’re afraid they won’t grow back, you have nothing to worry about.
Boston ferns are easy to revive out of dormancy because they stay semi-dormant without fully hibernating.
Plants will usually take a couple of weeks max to return from dormancy, and some will even make it back in a shorter time.
For your Boston fern to start growing back, move it to a place that gets plenty of indirect sunlight. Give it plenty of water and some fertilizer, and maintain the watering schedule until you see it growing back.
Now, the winter is over, the snow has melted, and the sun is peeking around the clouds. As the temperature returns to normal, it’s time to get your Boston ferns outside.
Of course, you won’t do it abruptly, or the plant will get fatigued trying to adapt to the temperature difference. Instead, you’ll let it acclimate to the new weather.
To do so, start moving the plant to a sheltered area with indirect sunlight for a few hours a day. As every day passes, keep the plant outside for longer, then bring it back inside. Keep doing so until the weather is entirely warm again and the spring is officially back.
When you feel that the plant is now used to the warm weather again, you can let it stay outside.
The thing with Boston ferns is that their roots are pretty thick. So, when it’s time to rehydrate them for the winter, you may have to do more than just watering them because the water will take some time to reach the deep roots.
The same goes when the soil is totally dried out; that’s why you shouldn’t let it reach this phase.
To rehydrate the plant, grab the entire container and put it in another large pot full of water. You can also use a pan or a bowl—whatever is available.
Leave the plant pot in the water for half an hour, then remove it. When you remove it, put it on a water drainer, and let it sit until it drains all the water inside.
After that, you can water the plant normally because it’ll have regained its moist state.
That’s a big fat no, and the same goes for any tropical plant.
Plants growing in tropical areas don’t see any frost during their lifetime. So, they’re not well-adapted to fight it, and the cold temperature will likely kill their roots and rhizomes, preventing any further growth.
If the weather is freezing cold in your area and snow is starting to show, that’s your cue to let your plant go dormant until spring comes around.
That’s unless you have a well-prepared room with a thermostat that can host the plant during the cold months.
Some plants can survive the frost, but only if you take them out of it fast enough—particularly before their roots and rhizomes are dead.
Let’s say that you forgot to move the Boston ferns inside before the snowstorm that’s been predicted on this week’s forecast. What do you do?
The plant is now frozen; can you revive it?
Well, that depends on the severity of the situation. If the roots of the plant are already dead and the rhizomes are too far gone, the plant sadly can’t recover.
On the other hand, if both the rhizomes and roots are still alive, you can indeed revive the plant.
Here’s how to do it.
The first thing you should do to save your frozen plant is to bring it inside. You shouldn’t bring it to your house suddenly because the abrupt temperature change will cause it stress.
Instead, keep it in a shed or any similar place, where it’s sheltered from the cold but not entirely warm.
Then, after the plant recovers from the initial shock, you can move it to the house.
Because the plant is frozen, the roots are likely not receiving as much water as they need. To fix that, you’ll need to rehydrate the plant by watering the pot well. The water should be lukewarm to thaw any frost in the soil.
It’s a common mistake to keep from watering the plant when it’s frozen. The way most people think, the roots are already iced, which is basically water. So, it definitely doesn’t need any more.
Well, that’s a huge mistake. The frost keeps the water from penetrating the roots, so the plant gets really dehydrated when it’s frozen.
After you water the plant, the only thing you have to do is to wait and see. Try not to give in to the temptation of pruning the plant or fertilizing it. That’ll only further stress the plant.
You’ll want to be patient and wait a couple of days to assess the root damage. If the roots are refusing to return to their original state, you can wrap an insulating plastic around the container to provide some warmth without overwhelming the plant.
As the days go by, you’ll notice some fronds falling off, which is normal because the cold likely damaged them.
When the fronds stop falling and the roots are back to absorbing water, you can now rest assured that the plant is saved.
You can then move it to its permanent place during the winter. If the plant needs it, you can also do some pruning to keep it from shedding.
When you’re sure the plant is revived, and everything is back in place, it’s time to clean the roots. The frost likely got the roots near the edge and damaged them, so you’ll need to remove those for the other roots to live normally.
Lift the plant from its container and gently take a look at the roots. You’ll have to remove the root ball and examine it closely.
If you find some black roots, those are dead, so you can cut them. Likewise, if there are some roots that are darkening in color and are softer than the ones around them, it’s only a matter of time before they die.
Remove all the cold-damaged roots because they may cause a fungal infection if they stay inside. Then, you can leave the plant to grow normally.
Generally, if your plant still has a couple of healthy fronds, its chances of survival are better.
Boston fern winter care may seem tough, but you only have to make major adjustments at the start of the season, then you can watch the plant live for the rest of the cold months.
You have two choices when it comes to Boston ferns in the winter: either get them inside or let them go into dormancy.
If you don’t have a suitable place to keep the fern in winter, it’s better to let it go dormant. To do so, store it in a cool, sheltered place and only mist it when necessary.
On the other hand, if the temperature inside your house doesn’t fall below 50 degrees, you can keep the ferns inside. To do that, make sure they get at least two hours of sunlight daily.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.