Heart Fern Care: Secrets To Thriving Heart Ferns

Heart fern (Hemionitis) is a plant that, according to some sources, belongs to the Hemionitidaceae family, while others place it in the Adiantaceae family. Both families include ferns.

The native habitats of this plant are the northern regions of America, where there is a tropical climate, as well as Vietnam, India, the Philippines, Laos, and Sri Lanka. There are eight different species within this genus. However, the most popular are Hemionitis arifolia and H. palmata, often used as houseplants.

Overview of Heart Fern

Attribute	Description
Soil	Loose, nutritious, well-draining, neutral pH. Recommended to use ready-made fern soil mix.
Size	9.8 to 15.7 inches (25 to 40 cm)
Blooming Time	January to December
Possible Colors	Green
Light Requirements	Moderate // Direct sunlight acceptable for a few hours, east or west orientation
Watering	High // Requires consistently moist soil (watering more than 3 times a week)
Care Difficulty	High // Demanding in care (cool wintering, supplementary lighting, protection in the garden, etc.)
Air Humidity	High // High humidity (60% or more: tropics year-round; typical summer humidity in temperate zones)
Fertilization Frequency	Moderate // Fertilize only during active growth (minimal during the dormant period)

Introduction to Heart Fern

The first description of this green world representative was made by Dutch botany professor Nicolaas Laurens Burman (1734–1793), who specialized in ferns, algae, and seed-producing flora specimens.

He made significant contributions to understanding the characteristics of such plants. The genus Hemionitis got its scientific name from the Greek word “hmi-onoj,” which means “barren fern.”

Physical Characteristics and Growth

Heart fern is a perennial plant distinct from its relatives within the same family. Its height ranges from 25 to 40 centimeters (about 10 to 16 inches). Due to its love for high humidity and small size, it is usually grown in terrariums.

The rhizome is covered with scale-like structures, which are modified leaves that help protect the plant and its growing points.

Like many ferns, its leaf blades are divided into two types: fertile (those that produce spores) and sterile.

Leaf Structure

The leaves of the Heart fern are quite large, reaching up to 25 centimeters (about 10 inches) in length. Their surface is leathery, shiny, and glossy with a rich dark green color.

The underside of the leaves is covered with fine hairs. The leaf blades can take on the arrowhead, heart, or fingered-lobed shapes.

They may have a pointed tip or a rounded end. Due to these characteristics, the Heart fern does not closely resemble other members of the fern family.

Reproduction and Growth Cycle

During spring and throughout the summer, Heart fern produces new leaves, while older ones gradually wither.

Interestingly, the bud near a sterile leaf (a baby plant) may awaken and give life to a young plant if the growing conditions are favorable.

When the baby plant develops its own roots, it will fall to the ground and successfully take root there. This is why this fern is considered “viviparous” or live-bearing.

Unique Properties and Planting Recommendations

Heart fern also has another interesting property: as it grows, it releases a substance into the soil that can inhibit the growth of other nearby plants, except other ferns.

Therefore, when growing it at home, it is recommended to use separate pots with individual trays for the plant.

Caring for Heart ferns is not particularly easy, and if you lack experience, you can easily harm the plant by not adhering to the proper care conditions outlined below.

Success Secrets for Growing Heart Fern at Home

1- Lighting and location selection

This fern requires diffused light – a north-facing window is suitable, while east or west locations require shading.

2- Temperature

During spring and summer, try to maintain temperatures between 23-28°C (73-82°F), with lower temperatures at night.

With the arrival of fall, lowering the temperature to around 16°C (61°F) is recommended.

3- Humidity

When growing Heart fern, maintain air humidity above 50%, although this fern can successfully adapt to lower levels.

Place the pot with the plant in a deep tray filled with moistened expanded clay or peat at the bottom.

Terrariums or aquariums can be used to make the Heart fern feel comfortable. Maintaining high humidity is essential, especially if the plant is kept indoors during the winter with heating devices turned on.

4- Watering

Remember that since ferns grow in moist substrates in tropical climates in the wild, the soil in the pot should never dry out.

However, overwatering and constant excessive moisture will lead to the root system of the Heart fern rotting.

Allowing the substrate to dry out is also prohibited, as the leaves will immediately begin to die. During hot summer days, you need to water daily.

Ensure the soil is completely saturated with water and the excess drains through drainage holes. After 10-15 minutes, remove any remaining water from the tray under the pot.

The soil on top can only dry out slightly between waterings. In winter, reduce watering, especially if kept in cool conditions.

Use soft water at 20-24°C (68-75°F) for watering. You can use river water, collect rainwater, or use distilled or bottled water.

If you want to know more about the watering frequency of ferns, check out this article.

5- Fertilizer Application

Fertilization for the heart fern is necessary every month during its active growth period, but you can also do it less frequently by applying half-strength mineral fertilizers.

The fern responds well to organic fertilizers (such as cow manure). Fertilization is discontinued during the winter months.

6-Repotting and tips for choosing soil

While the heart fern is still young, you need to repot annually, but as time goes by, repotting is only necessary when the root system fills the entire pot or the plant becomes too large.

It is recommended to use shallow clay pots due to the structure of the root system.

A drainage layer must be placed at the bottom of the pot, and small holes should be made at the base to allow excess water to drain after watering.

You can use ready-made commercial mixes designed for ferns, which have sufficient looseness and permeability for water and air.

You can create a DIY soil mix by combining equal parts of peat moss and compost if desired. Also, add chopped sphagnum moss and pieces of charcoal to the mix.

7- General care tips for heart ferns

Removing old fronds promptly and regularly dividing an overgrown plant is essential. You can use a soft brush to clean the dust on the leaves.

Heart Fern Propagation Rules

You can propagate this unique fern by dividing an overgrown plant, sowing spores, or planting “pups.”

During the summer, if the mother heart fern has grown significantly, you can divide it into parts.

First, carefully remove the plant from its pot and use a sharp, well-honed knife to cut the root system into pieces, ensuring that each division has enough leaves and several growth points.
Then, dust the cuts with activated wood charcoal or cinnamon powder. Plant the heart fern sections in separate pots with a drainage layer and appropriate soil mix.
Cover the divisions with a plastic bag and keep them shaded.

Propagation using spores can be challenging for beginners and doesn’t always yield positive results.

Propagate heart ferns using spores; their unique reproductive method bypasses flowering. — Propagate heart ferns using spores; their unique reproductive method bypasses flowering

To do this, scrape the mature spores on the leaves’ underside onto a piece of paper, place them in a paper envelope, and dry them.
Next, you’ll need a deep plastic container, preferably with a clear lid. Place a brick at the bottom of the container and cover it with peat moss.
Moisten the peat moss with a spray bottle, and pour water into the container until it’s about 2 inches deep.
Spread the spores on the peat surface, and cover the container with a lid or transparent plastic bag.
While germinating, maintain the recommended water level in the container and place it in a fairly shaded location. The temperature should be around 70 degrees Fahrenheit.

After a few months, you’ll notice a green, moss-like growth on the peat surface, followed by the formation of the first leaves.

Once the heart fern seedlings reach about 2 inches in height, you can transplant them.

You can also plant small offshoots (pups) that grow if the growing conditions are favorable, emerging from buds at the base of sterile leaves or along their edges.

When these pups develop enough roots, they naturally detach from the mother fern and root in the substrate. You can remove these pups from the heart fern and plant them in separate small pots.

Addressing Challenges: Preventing Diseases and Pests When Growing Heart Fern at Home

Since the plant is somewhat difficult to care for, even minor deviations from proper care can cause it to weaken.

As a result, it may be affected by the following harmful insects: spider mites, mealybugs, aphids, and scale insects.

If you notice signs of pests, wash the foliage under warm water streams (preferably a shower), and then wipe the leaves on both sides with an oily, soapy, or alcoholic solution.

However, this operation may be challenging, as some varieties have fuzz on both sides. Therefore, it is recommended to spray the plant with broad-spectrum insecticides.

Here are some issues of Heart Fern that may arise when care guidelines are not followed:

Wilting of the leaves occurs due to over-watering the soil in the pot, a drop in temperature, or excessive drying of the soil during hot weather.
Leaf tips begin to yellow and eventually dry out if the humidity levels in the room where the heart fern is kept are too low.
Leaf color fades and turns yellow if there is insufficient light.
Insufficient drainage and stagnant water in the tray can lead to rot.
Underwatering: Inadequate water can cause the plant to shrink, leading to curling leaves. Ensure that the soil remains consistently moist but not waterlogged.
Overfertilization: Excessive fertilizer can cause a buildup of salts in the soil, raising its pH and leading to leaf curling. Use a balanced, slow-release fertilizer and follow the recommended dosage.
Heat stress: Heart ferns prefer cooler temperatures and indirect sunlight. Excessive heat can cause stress, resulting in leaf curling. Place your fern in a shaded area, away from direct sunlight or heat sources.
Pests and diseases: Pests like aphids, mealybugs, or spider mites can cause leaf curling. Fungal infections, such as root rot or leaf spot, may also be the culprit. Inspect your plant for pests and signs of disease, and treat accordingly with appropriate insecticides or fungicides.

Insect Pests

Insect Name	Signs of Infestation	Control Measures
Mealybugs	Fluffy white, cotton-like residue on leaves and shoots. Slowed plant growth.	Home remedies: Spray with a soapy alcohol solution. Tobacco, garlic, cyclamen tubers, alcohol treatments, and neem oil have proven effective.
Spider Mites	Fine webbing on leaves, yellowing and leaf drop when extensively affected. Leaf surfaces become lifeless and develop small cracks. Plant growth slows down.	Home remedies: Rinse plants in the shower and leave them in a humid environment for half an hour. Chemical treatments: Pyrethrum-based products such as Natural Pyrethrin Concentrate.
Aphids	Sticky droplets on leaves, curled and deformed leaf plates, wilting buds and young leaves. Colonies of insects can be seen on shoot tips, buds, or the underside of leaves. Infested leaves may become deformed.	Home remedies: Nettle infusion, soapy solution, tobacco and dandelion infusion, onion, marigold, yarrow, tansy, dusting with wood ash. insecticidal soaps and oils are the most effective treatment.
Scale and False Scale	Sticky droplets on leaves, small yellow spots on leaf surfaces. Extensive infestation can cause leaf drying and falling. Plant development slows down.	Home remedies: Spray with a soapy alcohol solution. Scale insects dislike garlic infusion; Use pyrethrum-based products such as Natural Pyrethrin Concentrate.
Slugs and Snails	Holes in leaves, and slime trails on leaf surfaces.	Home remedies: Hand-picking, dusting plant leaves with mustard, hot pepper, wood ash mixed with baking soda, and tobacco dust. Chemical treatments: Superphosphate granules.

Interesting Facts About Heart Fern

Heart ferns that are available for purchase are usually quite young. When buying, the first thing to pay attention to (according to advice from plant growers) is the health of the plant.

It is essential to examine the fern for any signs of harmful insects carefully. Even if there are no visible symptoms, it’s still a good idea to put the heart fern in “quarantine” for a short period after purchase.

After 14 days, if everything is fine, you can place the fern on the windowsill next to other plants in its permanent location.

It’s important to note that although you can see spores on the underside of the leaves, germinating them indoors can be, quite challenging.

Some species of this fern, such as Hemionitis palmata, are grown in botanical garden conditions. They are unsuitable for home growing because they require a relatively humid environment.

Interestingly, the Hemionitis arifolia variety is used in Asian medicine to treat diabetes. This fern has also been medically evaluated for its hypoglycemic and antidiabetic properties in rats.

It was found that some of the extracts found in the plant lower blood glucose levels in rats fed with sugar, but only a small amount of hypoglycemic activity was observed in rats that were fasted overnight.

It is unknown whether the fern extracts can be used for human application. Healers traditionally grind sterile leaves into a paste, mix it with water, and then consume it for treating joint pain or burns.

Types of Heart Fern

1- Hemionitis Arifolia, Or Arrowleaf Heart Fern

This is a small fern that does not exceed 15 inches in length (40 cm). Its fertile leaves (sporophylls) have an arrowhead-triangular shape. The leaf surface is shiny on top, while the underside has a slight fuzz.

The sterile fronds also have a triangular shape but with a heart-shaped base. The leaves are 2 to 3 inches long (5 to 7 cm), and the stem reaches 6 to 10 inches (15 to 25 cm).

On the underside of the leaves, you can see the spores along the veins against a dark green background, and they have a dark red color.

This variety is often called a “heart-shaped fern” or “tongue-shaped fern.” Its Latin synonyms include Asplenium arifolium, Gymnogramma arifolia, Gymgogramma sagittata, Hemionitis cordata, Hemionitis cordifolia, Hemionitis sagittata, and Hemionitis toxotis.

It is mainly found in Laos, Sri Lanka, Vietnam, and possibly in China, Taiwan, and other countries in the tropical part of Southeast Asia.

The plant can comfortably grow on the ground or as an epiphyte on tree trunks or branches. This variety was first described in 1895.

2- Hemionitis palmata, Or Palmate Heart Fern

This type resembles the previous species but is distinguished by its fronds with lobe outlines. The sterile leaf blades are three-lobed or palmate.

The spores have a net-like appearance and an elongated contour with a brownish color. They are arranged along the veins.

The fertile fronds (sporophylls) have stalks that are almost twice the size of the sterile leaves, so these leaves rise above the rest of the plant.

This plant is perfect for terrarium or Wardian case conditions. Its native habitat is in the tropical forests of Central and South America. It is not very hardy and prefers to grow in the shade on moist, well-drained compost.

3- Hemionitis pinnatifida

You can find it with pinnate-divided frond outlines. Its native growing area is Central America. Other less popular varieties in the family include H. levyi, H. rufa, H. subcordata, H. tomentosa, and H. x smithii.