Why is my Boston Fern turning brown? Causes and Solutions

It’s important that you act as quickly as possible to resolve the issue as the earlier you catch the problem, the easier it will be to bring your Boston Fern back to full health.

Before you’re able to fix whatever it is that is causing your Boston Fern to turn brown, it’s important that you diagnose the problem properly. There are several different causes that will result in brown leaves on your Boston Fern, but they all have one thing in common; it’s important that you act as quickly as possible to resolve the issue as the earlier you catch the problem, the easier it will be to bring your Boston Fern back to full health. 

Below we will be going through each of the causes of brown Boston Fern leaves below, as well as how to fix the issue and prevent it from happening again in future. 

Intense light can cause brown leaves on a Boston Fern

Intense direct sunlight can cause brown leaves

Lighting is always an important element to take into consideration when caring for your houseplants and things are no different with the Boston Fern. If your Boston Fern is getting too much bright light you’ll start to notice browny patches throughout your plant. This is due to the sunlight burning the delicate leaves on your ​​Boston Fern which is unfortunately irreversible. To avoid this issue, we recommend moving your Boston Fern into a slightly shadier place, and if there’s no improvement move it a little further again until you find it’s the perfect spot. 

You can carefully trim away the brown leaves so your Boston Fern can focus all of its energy on new healthy growth.

Cold temperatures can cause brown foliage on your Boston Fern

Extreme temperatures 

Another factor that can harm your Boston Fern is really high or low temperatures. It can happen that your Boston Fern gets exposed to cold drafts coming in from outside, cold streams of air from AC vents or on the other extreme, warm air from radiators or cookers can dry out the plant. Either of these extremes may cause your ​​Boston Fern to develop brown crispy leaves. 

To avoid these extreme temperatures, ventilate the room well and keep all plants at least 1 metre away from radiators, heaters or cookers. You may also want to invest in a digital thermometer to keep track of how the temperature changes throughout the seasons and make sure your Boston Fern is in its ideal range to avoid brown leaves. 

A consistent lack of water 

If the leaves on your Boston Fern have gone quite brown but dry, then too little water might be why your ​​Boston Fern is struggling. If the soil is very powdery and dry then you should slowly reintroduce water to raise the moisture levels in the soil. ​​Boston Ferns really like moisture in the soil so don’t let them dry out for long periods of time.

Keep the humidity high for your Boston Fern!

Low humidity levels can cause dry brown leaves

If you’re confident that you’re keeping your watering habits in check, then low humidity could be the cause of your Boston Fern’s leaf browning. A common telltale sign of a lack of humidity is dry leaf edges before the whole leaf turns brown.

Luckily for all of us plant parents, there are several ways you can really easily (and cheaply) raise the humidity level for your Boston Fern: 

Mist the leaves daily

Use a spray bottle to mist the leaves once a day during summer and a few times per week during winter. This also helps to clean the plant so it’s a win-win!

Showering your Boston Fern

If you’re looking for a quick fix, washing down the leaves is a great way to boost the humidity for your ​​Boston Fern. Make sure when you do shower down your plant, that you’re keeping the water pressure low so you don’t damage the leaves/ stems.


If you have good lighting in your bathroom then we recommend moving your Boston Fern in there. The humidity level in those rooms is naturally higher because of showering and your ​​Boston Fern will love it in there! 

Buy a humidifier

If you’re worried about the lack of humidity becoming a real problem, then buying a humidifier is probably the best thing for you. It keeps the humidity in the room at a consistent level so you don’t have to worry about any more dry brown leaves developing on your plant. But the benefits of humidifiers don’t stop at your houseplants, they are even great at clearing our skin and helping us get a better nights sleep.

We always recommend this humidifier from Amazon as a great place to start.

Those are the four main reasons why ​​Boston Fern plants develop brown leaves. It can be quite a common issue for ​​Boston Fern plants as they are very sensitive and have super delicate leaves so just make sure you are staying on top of watering and boosting the humidity and this will go a long way to avoiding brown dry leaves. 

To find out more about how to best care for your fern, as well as how to spot and treat other common problems that might arise with your plant, check out our ​​Boston Fern care guide.

Written by Joanna Turner


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