Why Is My Boston Fern Going Brown In The Middle? (Causes+Fix)

Boston ferns are gorgeous, bushy green plants originating from the tropical regions. Although hardy plants, one common problem Boston ferns plants undergo is browning in the middle.

Browning in the middle is caused mainly due to low humidity, high temperatures, and exposure to direct sunlight. You can prevent brown leaves in Boston fern by using a humidifier, watering whenever the soil goes dry, and keeping the plant away from direct sunlight.

In this article, I will discuss the various reasons that lead to the browning of the Boston fern from the middle and suggest preventive measures to avoid this problem.

Why is my Boston fern turning brown in the middle?

In Boston ferns, it is normal for old leaves to get yellow and brown and fall off.

But if you see your entire plant, including the young leaves starting to get brown from the middle, it is a cause of concern.

This can be due to multiple stress causes, and it is important to recognize the problem and cure it if you wish your Boston fern to flourish.

Let us discuss the causes of the browning of the Boston ferns in the middle in detail. 

Low humidity

Boston ferns generally flourish in humidity above 80% in nature.

However, indoors they can do well in humidity above 50%, but anything below that can cause stress to the plant.

Our homes might have humidity that is extremely low for the ferns, and as a result, the Boston fern starts to turn brown and crisp from the middle.

This happens because the low humidity sucks the moisture from the ferns’ leaves.

Several factors in our homes further turn the humidity even lower in our homes.

• Air conditions turn the air dry inside our homes, making the fern brown from the middle.
• Heaters and fireplaces create heat currents in the homes which cause dry air in the homes. 

Also read: Should I Mist My Boston Fern? (How Often+Pros & Cons)

Underwatering

The reason for Boston fern turning brown can often be underwatering. 

Boston ferns like to be in evenly moist soil because, in nature, they grow under bigger trees that can hold a lot of moisture while it is porous enough to drain out the excess water from the roots.

If you leave the plant that is too dry and lacks moisture, the fronds start turning crispy and brown due to lack of moisture.

Also read: How To Water Boston Fern? (How Often, How Much & More)

Small pots drying out quickly

The leaves of Boston ferns can turn brown if the pot is too small for the plant or if the plant gets root-bound.

This is because they contain lesser soil which holds lesser moisture than the plant needs, so the roots absorb the available moisture very quickly, resulting in the brown leaves.

If the plant gets root bound, the roots will not be able to function properly.

This can lead to soil drying out quickly and the plant getting dehydrated and turning brown from the middle.

Also read: What Kind Of Pot Is Best For a Boston Fern? (Size, Material & More)

Too much sunlight

Though light is needed for plants to photosynthesize, houseplants cannot tolerate harsh direct light.

In nature, Boston ferns grow under the woodland canopy with filtered or dappled sunlight or in full shade.

Therefore they are not adapted to tolerate direct sunlight.

They are extremely sensitive to direct scorching sunlight.

If the Boston fern gets too much sunlight, that will cause the leaves to lose moisture faster.

Direct sun rays would also decrease the humidity around the plant and increase the plant’s temperature, resulting in the browning from the middle.

Also read: What Kind Of Lighting Does A Boston Fern Need?

Overfertilization 

Boston ferns are light feeders meaning they do not need too many fertilizers.

Overfertilization can lead to salt build-ups in the soil, leading to the browning of the fronds.

It may also damage the roots ad leaves of your Boston ferns.

Also read: Should I Fertilize My Boston Fern? (Ideal Fertilizer+When & How Much)

Extreme temperatures

Boston ferns grow in tropical countries, but they cannot tolerate extreme temperatures.

They cannot tolerate too high or too freezing temperatures.

If the temperature is too high, it increases the rate of transpiration from the leaves and the rate of evaporation from the soil, after which they start to appear yellow to brown and can get dry and crisp.

This is primarily because, in nature, when they grow at the foot of bigger trees with no direct sunlight, the temperature generally stays cooler in these areas, making them very sensitive to direct sunlight.

Also read: Boston Fern Temperature Tolerance: +Ideal Temperature

Outdoors ferns turn brown before winters.

The Boston ferns start appearing brown before the winters if they are kept outdoors.

This does not indicate they are dying but denotes that the outdoor ferns go through a cycle.

So when winter approaches, the temperature starts going low, and the air starts to turn dry, the outdoor ferns begin to go into dormancy. 

Also read: Are Boston Ferns Indoor Or Outdoor Plants? (+Care Difference)

Transplant shock

Sometimes the plant finds it difficult to deal with the stress of transplant if it is not done in the correct way and time.

While transplanting, sometimes the roots gt injured or damaged, which can lead to browning of the leaves and death.

Natural aging 

As the Boston fern matures and ages, it turns brown before falling off.

New foliage grows to take up its place.

This is a natural process, and one cannot prevent this.

It is best to prune away these dead foliage to keep the plant looking healthy and green.

How to prevent the Boston fern from browning in the middle?

We have discussed the various causes that might lead to your Boston ferns fronds going brown from the middle.

After knowing the issues, it is important to know how you can fix them.

So now we will explain the solutions you can follow to prevent the further browning of the fronds.

However, you should remember that browning is an irreversible process, and those already brown parts cannot be made green again.

By preventing the browning, you can protect the newer leaves from browning.

Maintain high humidity

To prevent this problem of browning the fern in the middle, you should try to increase the humidity around the home immediately.

You can shift your fern to high humid areas of your home like the bathroom, kitchen, or laundry room if they have good airflow and bright light.

There are several ways to increase the humidity artificially like: 

• Misting: The most common way to increase humidity in plants is by misting. Though its effects are short-lived, it is a cheap and simple way to raise humidity. The frequency of misting depends upon the weather. In scorching summers, you might need to mist multiple times per day.
• Grouping the plants together: Grouping together plants that like high humidity help to increase the humidity because grouping together gives off humidity creating a moisture-rich condition for all the plants. 
• Pebble trays: In this, you have to take a saucer and fill it with pebbles and water. Keep the pot on the layer of pebbles so that the water does not directly touch the plant’s bottom. This helps to increase moisture by the water evaporating from the plate.
• Humidifier: This gives the most long-lasting results. You have to fill the humidifier with distilled water and keep it near the plants. They create optimal humidity for the fern, which replicates its natural environment. You can also increase and decrease the amount of humidity around your need depending o the requirement around the plant. 

Correct temperature range

Keep the fern at a temperature range between 65-75°F.

It is advisable to keep them away from sunny spots like a balcony, a south or west-facing window, or an open garden.

It is also highly recommended to keep your ferns away from heaters, vents, air conditioners, and so on because these lead to drastic temperature changes.

You can use a digital thermometer near your Boston fern to check the area’s temperatures and then adjust the location as per the fern’s suitability. 

Finding the right spot

It is important to find the correct spot for your Boston fern that would suit it the most.

Outdoors, you must keep the Boston fern under the shade of the patio or a big tree or at a place where direct sunlight does not come.

Indoors you can keep your fern near a bright north facing widow or east-facing window which gets light morning sunlight but not the scorching afternoon sun.

If you keep it in a window, it is best to protect the fern from the sunlight by a sheer curtain.

You can also keep a larger plant to stand as a barrier between the fern and the direct sun to give some shade to the fern.

Water correctly

How frequently you water your Boston fern depends on the climate and temperature.

Do not water your Boston fern on a schedule; check the soil requirement and dampness to understand whether it needs water.

You must reduce watering in the winter months as houseplants tend to go into dormancy.

Also, the evaporation rate is much lower in winters, which keeps the soil moist for a longer period.

However, if you find it hard to understand whether the plant needs moisture, you can try and lift the fern pot.

If it feels light, your fern needs water, but it does not need water if it is heavy.

You can also dip your finger in the soil to check whether the soil sticks to your finger or not.

If it sticks, it does not need water as it already has enough moisture.

Otherwise, you can water.

You can also use a moisture meter to understand this.

Always water your Boston fern heavily until it flows out of the drain hole instead of light watering.

The correct way to transplant

To minimize transplant shock, always repot in spring and early summer. 

Because it is their growing period, it is easier for them to cope with the stress of transplantation.

Try not to damage or disturb the root ball by pulling it too harshly.

Be gentle and trim only the parts that appear to be lifeless. 

In most cases, the plant recovers from this shock after some days on its own without much disturbance.

In such cases, it is advisable to keep the plant in a cool shaded area with bright light and let it heal itself.

Fertilizing

Fertilizing twice a year, once in spring before fall, is enough for your Boston fern. 

Remember not to fertilize in dry soil and always water the fern a day before fertilizing to keep the soil moist.

Always make sure to apply the fertilizer on the soil and not on the fern leaves, leading to leaf burns.

If you see excessive salt build-ups on the soil, it is best to flush the soil thoroughly.

Water the pot fully and let it flush out of the drain hole for 5 minutes to help clean the excess salt in the plant.

Protect from winters 

Prune your Boston fern right when you see the first sign of browning at the beginning of winter.

You should cover the surface with compost mulch to help insulate the fern’s rhizomes.

Unless your area experiences cold, your Boston fern should bounce back in spring.

Repotting

You need to periodically repot your Boston fern to a pot that is 1-2 inches bigger to avoid root-bound plants.

Using fresh soil also helps in the availability of essential nutrients and moisture.

The plant would have more soil to retain moisture and essential nutrients in a larger pot.

It is also recommended to use pots with drain holes to avoid root rot. 

Remember to trim off all the dead and yellow leaves when repotting. 

How to keep your Boston ferns healthy?

• Protect your Boston fern from direct sunlight as that will lead to drying up the leaves leading to browning and yellowing. 
• Your Boston fern does not like temperature fluctuations so keep it in a place that remains cool and away from heaters, vents, etc. 
• Boston ferns require high humidity, for which you must use artificial ways to increase the humidity through pebble trays, misting, humidifiers, and so on.
• Make sure the soil of your Boston fern remains constantly moist without being soggy. Do not keep the soil dehydrated as that will be very harmful.
• Protect your Boston fern from frost and extremely cold temperatures by bringing it indoors in areas of harsh winters. 
• Feed your Boston fern with compost or liquid fertilizer in the growing season.

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Reference: University of Florida, The University of Arkansas Division, Texas A&M University System, The University of Georgia, University of New Hampshire, Wikipedia, The Royal Horticultural Society.