How to Revive a Dying Fern

A dying fern is usually because of underwatering or the humidity is too low which saps moisture from the leaves causing them to turn brown and crispy. Indoor ferns prefer a humidity of 50% and require the soil to be consistently moist to prevent the leaves from turning brown and dying.

Most indoor ferns (such as Boston, Maidenhair, Birds nest, Rabbit foot, Asparagus ferns, etc.) are native to tropical climates where they thrive in high levels of humidity, consistently moist soil, cool stable temperatures, and in shady conditions under a woodland canopy.

To revive a dying fern it is important to replicate the fern’s native environment by increasing the humidity, planting the fern in moist organic soil, and locating the fern in a shady area at a stable and relatively cool temperature.

Keep reading to learn why your Indoor and outdoor fern is dying and how to implement the solutions to revive your dying fern…

Fern Turning Brown, Drying Out and Dying (Indoors)

• Symptoms. Fern leaves drying out with a brown appearance. Often just the tips of the fern leaves turn brown and dry.
• Causes. Low humidity, high temperatures, excessive airflow (from air conditioning or convection currents from central heating) too much sun, or because of underwatering.

The reason for ferns turning brown is because of low humidity, underwatering, or high temperatures. Ferns require a humidity of 50% to 70%, temperatures of between 65°F to 75°F, and require soil that is moist, but not saturated. Ferns turn brown due to stress from low humidity, excessively hot or cold temperatures or dry soil.

The reason low humidity is the most common cause of ferns turning brown is that ferns of all types prefer a humidity of at least 30% whereas the air in most homes tends to have a humidity of 10% and it is this dry air that causes the leaves to turn brown.

Ferns are woodland plants that thrive under the canopy of woodlands and forests and do not tolerate dry air or draughty areas of the home as this is in significant contrast to their natural conditions where relative humidity can be as high as 70%.

Low humidity is most often caused by:

• Too much sun
• High temperatures
• Forced air or air conditioning
• Sources of indoor heat
• Draughts from opening and closing doors or heat convection currents around the house.

This causes the ferns to turn brown usually at the tips and for the leaves (or blades) to turn crispy and die back. Some species such as Boston ferns drop their leaflets or turn brown as a response to humidity lower than 30%.

Along with low humidity, underwatering is the other most common cause of ferns turning brown and dying.

Ferns require the soil to be consistently and evenly moist for the fern to remain green.

If the soil dries out between bouts of watering the leaves turn brown and crispy with a wilting appearance.

Ferns only require light amounts of fertilizer when they are actively growing or if the leaves are light green (which indicates a lack of available nutrients).

If fertilizer is applied too often or in too high a concentration then it can burn the fern’s sensitive roots which causes the tips of the fern to turn brown with a dying appearance.

How to Revive Brown, Drying Out, Crispy Fern Leaves

To revive ferns with leaves turning brown and drying out it is important to recreate the humid conditions of its native environment by creating a humid micro-climate around the fern in your home.

• Place your fern in a room that is naturally higher in humidity such as a bathroom or kitchen. The air in a bathroom tends to be far more humid than any other room in the house and most closely resembles the humidity of the fern’s native environment which reduces water loss from the leaves and prevents them from drying out.
• Place the potted fern on a saucer or tray filled with water but propped up on pebbles. The water underneath and around the pot evaporates which creates a humid micro-climate around the leaves of your ferns which mimics its preferred natural humid conditions and prevents the fern’s leaves from turning brown. Keep the pot above the water line, so that the soil does not become saturated which causes root rot
• Water ferns so that the soil is consistently moist, but not saturated. Ferns grow in soil with lots of organic matter which retains moisture around the roots consistently yet is still well draining so that the roots are not sat in boggy soil. Plant ferns in good compost with lots of organic matter and water as often as required so that the soil is evenly moist (Exactly how often varies on your climate and conditions but if the leaves are turning brown and dying, and the soil feels somewhat dry then you are likely underwatering your fern.
• Always water ferns with a good soak rather than a light watering. Watering generously ensures that the moisture reaches the fern’s roots where it is required so that the roots can then transport moisture to the leaves so that they do not turn brown and crispy. Watering too light causes the surface of the potting soil to be moist but the water does not reach the roots where it is required. Always water thoroughly, so that excess water trickles from the base of the pot.
• Place the fern in a shady area and keep it out of full sunlight. The great thing about ferns is that they can thrive in shady spots so find an area of your home that does not have direct sunlight as this can scorch the leaves and dry out the soil causing brown leaves.
• Water the fern with lukewarm water rather the hot or cold water. Most indoor ferns are tropical plants and watering with lukewarm water replicates their natural conditions. If the water is very cold then this can cause shock to their sensitive roots which can contribute to the leaves turning brown.
• Locate the fern in an area that does not have draughts or air currents from air conditioning or forced air. As the temperature fluctuates during the year, the turning on and off of heating and air condition creates variable conditions for ferns which cause them to turn brown as a sign of stress. Place your fern in a draught-free area to reduce water loss from the leaves.
• Create a more humid environment with more nearby plants. By placing several leafy houseplants close together you can help create a humid micro-climate around your fern which can contribute to reviving your fern and replicating the sort of growing conditions in the fern’s natural environment.

• The best thing you can do for reviving ferns is to buy a humidifier. This is easily the best way to create the humid conditions around your fern which emulates its natural humid conditions. With a humidifier, you can achieve the optimal level of humidity for ferns to thrive as you can precisely set the percentage of humidity to exactly match the fern’s preference. Whilst other means of increasing humidity can contribute to reviving your fern, a humidifier is much more effective.
• Misting ferns with a spray bottle can also help, however, it is important to note that misting some species of ferns can increase the risk of foliar leaf spot disease if misted daily the leaves are consistently damp, so a humidifier is often preferable.
• Prune down any brown growth back to healthy green growth with a sharp pair of pruners. The brown leaves of the fern do not recover, but pruning them back can help to stimulate new healthy, green growth and improve the appearance of the plant.

By creating a more humid environment with a few adjustments, you can effectively recreate the fern’s natural conditions which reduces water loss from leaves and prevents the leaves from turning brown and drying out.

Once the conditions are to the ferns preference then the plants should perk back up and whilst some growth may remain crispy, particularly at the tips, new growth should emerge in the growing season.

(To learn more read my article, why is my fern turning brown?)

Fern Turning Yellow and Drooping

• Symptoms. Fern leaves turning yellow and drooping.
• Causes. Watering too often, so that the soil is saturated, rather than consistently moist. Pots without drainage holes in the base. The use of saucers and trays underneath the pot prevents excess water from escaping properly, causing water to pool around the base of the fern.

The reason for a fern turning yellow is because the soil is too damp from overwatering. Ferns prefer the soil to be consistently moist but also well-draining. If the fern’s potting soil is saturated then the leaves turn yellow and droop with a dying appearance.

Ferns grow naturally in rich organic soils that retain moisture yet have a well draining structure that allows excess water to drain away from the roots, so that the surrounding soil does not remain boggy.

By far the most common reason for ferns turning yellow and drooping is that the potting soil is too damp around the fern’s roots. This is typically for three reasons:

1. Water the fern too often so that the soil is saturated, rather than just consistently moist.
2. The use of saucers and trays underneath the pot causes water to pool around the bottom of the pot and the soil around the roots is boggy.
3. The use of decorative outer pots that do not have drainage holes and cause excess water to pool around the roots of your fern.

If the soil around the roots is consistently boggy around the ferns roots, then the water excludes oxygen from the soil and prevents root respiration which interferes with the roots ability to draw up moisture and nutrients.

If the fern’s roots cannot uptake moisture and nutrients to transport to the leaves then the fern’s leaves turn yellow and droop as a sign of stress.

If the fern’s roots are in boggy soil for too long, then this promotes the conditions for root rot and the fern turns yellow, droops, and dies back.

However, it should be noted that whilst boggy soil and root rot are the most common reasons for yellow fern leaves, due to the diversity of indoor ferns (most of which are tropical) yellow leaves can also be a sign of stress due to low humidity.

How to Revive Dying Indoor Ferns with Drooping, Yellow Leaves

To revive ferns with yellow, drooping leaves, it is important to recreate the well-draining soil conditions of the fern’s native environments and ensure that the fern’s roots are not sat in saturated soil which causes root rot.

• Water your fern as often as required so that the soil is consistently moist but not saturated. Exactly how often you water ferns depends on the size of the fern, the humidity of the room, and how well your potting soil retains moisture. Avoid soaking your fern every day as this can exude the oxygen from the soil and deprive the roots of oxygen, preventing root respiration.
• Plant ferns in potting soil with lots of organic matter. Good quality potting soil with lots of organic matter helps to retain moisture to provide the fern’s roots with the consistent moisture that they require yet has a porous structure that allows excess water to drain effectively so that the soil does not become waterlogged. If you notice your soil is draining particularly slowly after watering then check that the pot’s drainage holes are not blocked and consider changing your potting soil.
• Always plant ferns in pots with drainage holes in the base. Whilst ferns are adapted to consistently moist soil they also require good drainage to avoid root rot. Choose a pot with drainage holes in the base to allow excess water to escape.
• Ensure saucers and trays underneath your potted fern do not prevent water from draining from the soil to avoid yellow leaves. Ferns require high humidity which is why it is recommended to place your potted indoor fern on a tray filled with water and prop the pot up above the water line with pebbles. However, there must be space between the water line and the base of the fern’s pot so that water can escape efficiently from the drainage hole so that water does not pool around the roots of your fern.
• Empty decorative outer pots of excess water after watering. A common mistake when growing indoor plants in general is to plant the fern in a good pot with drainage holes in the base and then place the pot in a larger, more decorative outer pot that looks more stylish. The problem is that the outer pot often does not have drainage holes and excess water pools around the roots causing the leaves to turn yellow due to root rot.
• Check that the drainage holes in the base of the pot are not blocked by compacted soil. If there is compacted soil at the base of the pot then this can sufficiently slow the drainage to cause root rot. If the soil appears to be draining slowly after watering and the drainage holes are blocked then I recommend repotting your fern to a different pot with new soil to allow for good drainage after watering.
• Prune away any yellow leaves with a sharp pair of pruners as this growth does not recover. Pruning helps to stimulate new growth, prevents fungal problems, and improves the appearance of the plant. This promotes new healthy green growth. Wipe the blades of the pruners with a cloth soaked in disinfectant after each cut to prevent the spread of fungal pathogens to otherwise healthy growth.

If the fern is drooping and turning yellow then correcting the watering practices so that the soil is consistently moist but not saturated, and ensuring water does not pool around the roots can help revive the fern.

If the fern’s roots have been in boggy soil for too long it is likely to develop root rot and die back.

Why is my Indoor Fern Losing Leaves?

• Symptoms. Leaves or leaflets drop and potentially turn brown and crispy.
• Causes. Low humidity and underwatering and excessively hot or cold, tropical ferns.

The reason ferns lose their leaves is because of low humidity and underwatering. Indoor ferns are tropical ferns that require a humidity of at least 50% and prefer consistently moist soil. If the air is too low in humidity, or the soil is too dry the fern drops its leaves to help conserve moisture.

The majority of houseplant ferns (Boston ferns, Maidenhair ferns, Rabbit’s foot ferns, Holly ferns, etc.) are native to tropical or subtropical regions of the world where the humidity is much higher than it is typically within our homes.

The dry air saps moisture from the leaves of the fern, often quicker than moisture can be drawn up by the roots.

The plant reacts by drooping its leaves or leaflets which reduces further water loss as a survival strategy to conserve resources.

Consistent low humidity is one of the most common causes of dying ferns.

Low or high temperatures that are significantly out of the fern’s preferred temperature range of 65°F to 75°F is often also a contributing factor to ferns losing their leaves.

The symptom of ferns dropping leaves or leaflets is often in conjunction with the ends of the fern’s leaves turning brown as the causes are usually the same and indicate an environmental problem.

How to Revive a Fern Losing Leaves

The three most common causes of fern plants losing their leaves are underwatering low humidity, and temperatures that are too hot or too cold.

So to revive a fern losing its leaves it is important to correct the environmental conditions with higher humidity, watering more often so that the soil is consistently moist, and keeping the temperature within a range of 65 ℉to 75℉ and new leaves should start to grow.

• Increase the humidity to 50% with a humidifier. The best way to increase the humidity around your fern is with a humidifier as it is the most effective method and some humidifiers allow you to control the exact humidity so that you can precisely mimic the higher humidity conditions of the fern’s tropical native environment. This reduces water loss from the leaves and creates the optimal environment for your fern to start growing new leaves and start recovering.
• Place your fern near other potted plants and mist every day. If you group several plants near each other, you can create a humid micro-climate which is more favorable for your dying fern. Misting helps to reduce water loss from the leaves and your fern shoulder starts to revive.
• Water the fern as often as required so that the soil is consistently and evenly moist. There is no universal advice when it comes to a schedule for watering ferns as watering varies according to the size of the fern and the humidity of the room. However, I recommend feeling the soil to a finger’s depth frequently to ensure that the soil feels moist but not saturated. Always water with a good soak, so that excess water emerges from the drainage holes in the base of the pot, to ensure that the moisture has reached the roots where it is required.
• Keep the temperature between 65℉ and 75℉ and slightly cooler at night to revive your fern. Higher temperature cause more evaporation which increase the risk of leaves dropping and low temperatures cause stress to tropical ferns. Keep the temperature within the optimal range to replicate the fern’s natural environment for the fern’s leaves to revive.
• Keep your fern away from sources of heat, air currents, and draughts. The right level of humidity is essential for your fern to revive, so keep your fern out of any draughts or away from artificial heat which can sap moisture from the leaves.

With the optimal environmental conditions, the fern should revive and new leaves should emerge during the growing season.

Why is My Fern Dying Outside?

• Symptoms. Leaves turning brown, crispy, and dying back.
• Causes. Too much sun, soil drains too quickly, not enough water, or the area is too windy which saps moisture from the fern.

The reason for a dying fern outdoors is because of cold weather, too much sun, not enough water, or the soil drains too quickly for the fern’s roots to draw up moisture which causes the fern to dry out and turn brown with a dying appearance.

Ferns are woodland plants that grow in the shaded canopy with perhaps only dappled light or bright indirect light.

The leaves of the fern are very sensitive to direct sunlight which causes them to dry out and turn crispy.

Direct sunlight also increases the amount of evaporation from the soil, water loss from the leaves, and lowers the humidity which creates a hostile environment for the outdoor fern.

Ferns require the soil to be consistently moist and grow naturally in soil with a high organic content, due to leaf litter falling every year, creating a natural mulch.

Leaf litter and the woodland soil help retain lots of moisture around the fern’s roots, yet also have a porous structure that allows excess water to drain away so that the soil does not become boggy.

If the soil in your garden soil is too dry and sandy or stony then the roots of the fern cannot draw up enough moisture which causes the leaves to turn brown due to drought stress.

Outdoor ferns are also not necessarily evergreen and the leaves turn brown with a dying appearance in the Winter as a response to seasonal change.

Whilst the leaves can die back in Winter, the rhizomes are insulated under the soil and new healthy green leaves can emerge in the Spring.

How to Revive a Dying Outdoor Fern

The key to reviving dying outdoor ferns is to transplant the dying fern to an area of the garden that has more favorable conditions with dappled light, moist soil amended with lots of compost, protection from wind, and watering as often as necessary so that the soil is consistently moist.

• Transplant the fern to an area of the garden with amended soil. Before replanting the fern add lots of leaf mold, compost, or manure to the soil to a depth, of around 12 inches and 12 inches across to accommodate the root system. This replicates the soil conditions of the fern’s native environment retains lots of moisture and allows excess water to drain away, to prevent the soil from becoming boggy.
• Plant the fern in a shaded area that is out of the wind. One of the best characteristics of ferns is that they can grow in the shadier spots of your garden. The shade helps to reduce water loss from the leaves and evaporation from the soil and the surrounding plants, trees, or structure that provides the shade also acts as a windbreak which prevents too much moisture from being sapped from the leaves by a strong wind.
• Water the soil is often as required so that it is consistently and evenly moist. Once established and in optimal conditions, ferns often do not need any additional watering, however, whilst the fern is dying or turning brown, keep the soil moist to help it revive.
• Apply a 2-inch layer of mulch around the fern in the Spring. A mulch composed of compost, leaf mold, and well-rotted manure applied to the surface of the soil around the fern helps to improve soil structure, retain moisture, and add nutrients to the soil. Applying the mulch at the start of Spring helps to keep the soil at the optimal moisture level during the hot and dry weather of Summer.
• In Winter cut back any dying brown foliage to keep your garden looking tidy. The leaves of ferns tend to turn brown at the end of Fall at which point you can cut them back with a sharp pair of pruners and compost them. Applying a layer of mulch over the top of the fern can help to insulate the rhizomes from frost and cold which gives the fern a head start the following year. Green growth should emerge in the Spring.

Why is My Fern Turning Light Green?

The reason your fern is turning light green is because of a lack of nutrients in the soil. Ferns require repotting every year or so with new potting soil and additional fertilizer in the growing season to stay a healthy darker green rather than light green. Too much light can also turn ferns light green.

If your fern’s leaves are turning light green then this is not an indication the fern is dying but it is suffering due to a deficit in nutrients in the soil.

This can be because the fern has been in the same pot for too long and the roots have exhausted the potting soil of available nutrients or because of a lack of fertilizer.

Check whether the fern’s roots are pot-bound to determine whether you need to re-pot the fern. If so choose a pot the next size up and repot your fern with good-quality potting soil.

Use an all-purpose liquid house plant fertilizer at half concentration (ferns can be sensitive to higher doses) every 2 weeks during the growing season to revive your fern.

Key Takeaways:

• A dying fern is usually because of underwatering or low humidity due to air currents indoors. Typically the humidity indoors is around 10% whereas ferns require a higher humidity of 40%. Low humidity causes the leaves to turn brown, crispy, and dry out with a dying appearance.
• The reason indoor fern leaves turn brown is because of low humidity, high temperatures or the soil is too dry. Ferns prefer a humidity of at least 40%, consistently moist soil, and temperatures of 65°F to 75°F. If the temperature is too high or the air and soil are too dry, fern leaves turn brown, dry, and crispy.
• Fern Leaves turn yellow and droop because of overwatering. Ferns require the soil to be consistently moist, but not saturated. If the soil is too damp this excludes oxygen from the soil and prevents the fern’s roots from drawing up nutrients and moisture from the soil which causes the leaves to turn yellow and droop.
• The reason ferns lose leaves is because of low humidity and dry soil. Indoor ferns are tropical plants that require high humidity and consistently moist soil. If the humidity is too low or the soil is too dry, ferns drop their leaves as a survival strategy to reduce further water loss.
• A dying outdoor fern is usually because of underwatering, too much sun, or soil that drains too quickly. Outdoor ferns grow best under trees as they require protection from the sun and wind. Plant outdoor ferns in soil amended with compost to ensure there is enough moisture to prevent the leaves from turning brown and dying.
• Ferns turn light green because of a lack of nutrients in the soil. If the fern has exhausted all the nutrients in the potting soil the the leaves turn light green and the leaf growth is much slower. Too much sun can also turn the leaves a light green.
• To revive dying ferns, emulate the fern’s natural environment with higher levels of humidity, and shade, and water the fern as often as required to ensure the soil is consistently moist. Cut back any brown, yellow, or dying leaves to help stimulate new growth and revive the fern.