Complete Guide To Heart Fern Care and Growth

Quick Overview

The heart fern is a small, low-growing evergreen fern that reaches heights of only 6-10 inches tall and wide. It features delicate fronds emerging from black stems, with mature fronds growing in a lovely heart shape that gives this plant its common name.

While slow growing, the heart fern is prized by houseplant enthusiasts for its unique foliage and compact size, allowing it to thrive in terrariums and small indoor pots. It has also been called the tongue fern and is known by the botanical name Hemionitis arifolia.

Native Habitat and Origins In the wild, heart ferns grow as epiphytes, meaning they attach their roots to other plants and objects like trees and rocks. They are native to the tropical forests and jungles of Southeast Asia.

Heart ferns typically grow in shaded, humid conditions beneath the canopy layer of the forest. Here they receive filtered sunlight and consistent moisture from frequent rains. Temperatures remain warm year-round.

The heart fern was first described scientifically in 1753 as Acrostichum aureum by the Swedish botanist Carl Linnaeus. In 1859 it received its current botanical name Hemionitis arifolia from the British botanist Thomas Moore.

Ideal Light for Heart Fern

One of the keys to growing heart ferns successfully indoors is providing the right amount and type of light. In their native jungle habitat, heart ferns grow underneath the forest canopy where they receive bright but indirect light filtered through the overhead trees.

When grown as houseplants, heart ferns do best in bright, indirect light. Place your heart fern near an east or west-facing window where it will receive gentle morning or afternoon sun. You can also place it several feet back from a bright southern window where light is diffused.

Avoid direct sunlight, especially hot mid-day sun from a south or west window, which will scorch the delicate foliage. Rotate your plant occasionally to prevent uneven growth towards the light source.

Light Considerations

If adequate natural light from windows isn’t available, you can supplement with full spectrum grow lights. Position the lights 2-4 inches above the fronds for 12-16 hours per day. Grow lights help mimic the shaded conditions heart ferns prefer.

Insufficient light will cause leggy, weak growth. Check for foliage that turns pale green or yellowish, a sign more light is needed. However, too much light leads to dried fronds, brown leaf edges, and stunted growth.

How to Water Heart Fern

Heart ferns require consistently moist, but not soggy, soil to thrive. Inadequate watering is one of the most common causes of decline in indoor heart ferns.

Water your heart fern whenever the top 1-2 inches of soil become dry. Use your finger to test moisture levels and water thoroughly until it drains from the container’s bottom drainage holes.

This frequent watering schedule generally means watering heart ferns every 5-7 days on average. Water less frequently in winter when growth slows. Increase frequency in hot, dry conditions that accelerate soil drying.

Watering Tips

Always water in the morning to allow excess moisture time to evaporate from the fronds, preventing possible fungal disease. Avoid watering at night.

Ideally, use distilled or rainwater rather than tap water, which may contain salts and chemicals that can burn the fronds. If using tap water, let it sit out overnight before applying to allow chlorine to dissipate.

The potting soil needs to dry out moderately between waterings to prevent root rot. But long periods of drought will quickly damage this moisture-loving plant. Consistent soil moisture is key!

What Kind of Soil Does Heart Fern Like?

To grow well, the heart fern requires an organic, porous potting mix that retains moisture but also drains well. Aim for a soil pH between 5.5-7.0.

The ideal potting mix contains:

• Peat or coconut coir to retain moisture.
• Orchid bark or perlite for drainage and aeration.
• Compost, worm castings, or leaf mold to provide nutrients.
• Charcoal to keep soil pH steady.

You can make your own mix by combining equal parts coconut coir or peat moss, orchid bark, compost, and horticultural charcoal. Or use an off-the-shelf organic potting soil blended specifically for ferns and tropical plants, following label directions.

Soil Management

Soil for heart ferns should remain moist but never become waterlogged. Allow the top few inches to dry out slightly between thorough waterings. Add extra perlite or orchid bark to increase drainage in heavy, dense potting mixes if needed.

Re-potting into fresh soil annually in spring will refresh the growing medium and provide new nutrients.

How to Fertilize Heart Fern

Heart ferns are light feeders that only need occasional fertilization during the active growing season. Never fertilize in fall or winter when growth has slowed.

From spring to summer, feed monthly using a diluted balanced liquid fertilizer like 20-20-20 mixed at 1⁄4 to 1⁄2 strength. Or you can use an organic fertilizer diluted to the same ratio.

Alternatively, top dress in spring with a slow-release granular fertilizer or sprinkle worm castings around the base. Follow label directions carefully to avoid fertilizer burn.

Fertilizing Tips

Reduce watering before and after feeding to prevent root damage or leaf burn. Only fertilize when the soil is moist, never when dry.

Signs your heart fern needs more nutrients include stunted growth, pale fronds and yellow lower leaves. But excess fertilizer can also cause leaf burn, so start conservatively with lower dosage rates when in doubt.

Ideal Temperature Range

As a tropical jungle plant, the heart fern thrives in consistently warm temperatures between 60-80°F (16-27°C), with a minimum nighttime temperature around 60°F (16°C). Avoid exposing it to temperatures below 55°F (13°C) for extended periods.

Ideal daytime temperatures are 70-75°F (21-24°C). Growth may slow if the temperature drops below 65°F (18°C).

Temperature Management

Position your heart fern away from drafty windows or doors and ducts emitting cold air flow. Maintain indoor temperatures using a portable space heater as needed during cold weather.

The heart fern can tolerate hotter summer temperatures above 80°F (27°C), making it a good choice for rooms without air conditioning. However, temperatures above 90°F (32°C) may impact growth.

Monitor your plant closely if temperatures swing above or below the optimal range and make adjustments to ensure the foliage doesn’t suffer. Stability is key.

Ideal Humidity

How to Boost Humidity Indoors

Some tips for providing adequate humidity include:

• Use a humidifier to raise humidity levels in the room.
• Place the plant on a pebble tray filled with water and stones to create localized humidity through evaporation.
• Group plants together to take advantage of their collective transpiration.
• Mist fronds occasionally using room temperature purified water.
• Grow the heart fern in an enclosed terrarium or greenhouse cabinet to create a humid microclimate.
• Avoid positioning near heat sources like radiators or heating vents that can dry the air.

Humidity Warning Signs

Flowering Habits

Varieties and Cultivars

Hemionitis Arifolia

Hemionitis Arifolia ‘Minor’

Hemionitis Palmata

Hemionitis Subcordata

Crested Heart Fern

Repotting Needs

Heart ferns like their roots somewhat confined and don’t need frequent repotting. Repot every 2-3 years in early spring before intense summer growth begins.

Choose a container 1-2 inches wider than the current pot. Avoid overpotting. Drainage holes are mandatory.

How to Repot

Gently loosen the root ball and divide or tease out congested roots before placing into the new container filled with fresh potting mix. Top dress with worm castings.

Trim off any dead or damaged roots. You can also divide especially overgrown plants into smaller sections using a clean sharp knife before repotting.

Water thoroughly after repotting and keep out of direct sun while establishing. Mist leaves to increase humidity. Repotting stimulates dense new growth.

When and How to Prune

Pruning is needed occasionally to maintain a tidy appearance and healthy growth. Use clean, sterilized scissors or pruners when pruning to prevent disease spread.

Remove any dead, damaged, or diseased fronds at the base. Also prune away overlong fronds that are unsightly or becoming leggy and weak.

You can trim fronds by up to 1/3 their length if desired to shape the plant. Avoid removing more than this, as it can impact the plant’s ability to photosynthesize and produce energy.

Routine pruning encourages bushier, compact growth and better frond circulation and air movement, reducing pests and diseases. Prune as needed throughout the growing season.

Propagation Methods

Propagating by Division

Propagating by Spores

Heart ferns naturally reproduce via microscopic spores housed on the undersides of fronds. While more challenging, new plants can be grown from spores.

Choose a brown, papery frond displaying visible spore cases on its underside. Remove this fertile frond and seal it inside a plastic bag for 1-2 weeks. This drying period causes the spores to release.

Next, sow the spores thinly atop sterile seed starting mix or vermiculite. Enclose the container inside a clear plastic bag to retain humidity. Partial sunlight is needed for germination. Light misting helps maintain moisture levels.

After 2-3 months, tiny gametophyte plants should develop. Allow another 6-9 months for small ferns to form and grow larger before transplanting into pots. Maintain warm, humid, bright conditions at all times.

Pests That May Affect Heart Ferns

The Heart Fern’s high humidity requirements, often necessitating a terrarium, can protect it from many common pests. However, if conditions are not ideal or if it’s introduced to an infested area, it can still have issues.

• Fungus Gnats - This is the most likely pest. The constantly moist soil that the Heart Fern needs is a perfect breeding ground for these small, flying insects. Their larvae in the soil can damage the plant’s very fine, delicate root system.
• Mealybugs - These small, white pests can hide on the undersides of the heart-shaped leaves or at the base of the stems (petioles).
• Aphids - May be attracted to the tender new leaves as they emerge, causing them to be misshapen.
• Spider Mites - While they prefer dry air, a stressed Heart Fern in a less-than-ideal environment can become a target.
• Whiteflies – Tiny, moth-like insects that fly up in a cloud when the plant is disturbed. They cluster on the undersides of leaves to suck sap, leading to yellowing and sticky residue. Use yellow sticky traps and insecticidal soap to control them.

Due to the plant’s sensitivity, use gentle treatments like wiping with a damp cloth or using heavily diluted insecticidal soap with caution.

Troubleshooting Heart Fern Issues

The Heart Fern is notoriously finicky and considered a difficult houseplant. Almost all of its problems stem from its extreme need for very high humidity and its intolerance for both drying out and soggy soil.

• Brown, Crispy Edges - This is the most common and fastest-acting problem. If the humidity drops even slightly, the leaves will immediately crisp up, shrivel, and die. This plant cannot survive in average household humidity and requires a terrarium or cloche.
• Root Rot - This is the second major killer of Heart Ferns. While it needs to stay consistently moist, its roots are incredibly fine and will rot instantly in waterlogged, dense soil. It must be planted in a very airy, well-draining mix.
• Wilting & Drooping - The leaves will wilt when the plant is thirsty. However, they will also wilt when the plant has root rot because the damaged roots can no longer absorb water. Always check the soil before watering a wilting Heart Fern. If the soil is wet, wilting means root rot has set in.
• Leaf Drop - A stressed Heart Fern will quickly drop its leaves. This is its reaction to almost any issue: low humidity, underwatering, or overwatering.
• Brown-Black Spots - Fungal or bacterial spots can easily form on the leaves in the high-humidity environment it needs, especially if there is not enough air circulation inside its container.
• Stunted Growth - If the plant is not actively producing new heart-shaped leaves, its environmental conditions are not being met. It needs more warmth, higher humidity, or better indirect light.
• Edema – These are not pests, but water-filled bumps or blisters on the leaves caused by inconsistent watering. The roots absorb water faster than the plant can transpire it, leading to ruptured cells that look like scars or spots.
• Sunburn or Leaf Scorch – Appears as large, bleached, white, or crispy brown patches on leaves exposed to too much direct sunlight. This is damage from intense light and heat, not a disease.
• Nutrient Deficiency – Can manifest as slow or stunted growth, pale or yellowing leaves, and a general lack of vigor. It indicates the plant has exhausted the available nutrients in its soil and requires feeding with a balanced fertilizer.

Creative Ways to Showcase Heart Fern

Terrariums

Mounted Displays

Mix with Other Plants

Accent Shady Spots

Highlight Textural Contrasts

Expert Advice

Maximizing growth potential and keeping your heart fern looking its best involves paying attention to optimal care, troubleshooting issues promptly, and providing ideal conditions.

✅ Acclimate new plants gradually to your home over 2-3 weeks before fully transitioning. 💧 Use distilled or rainwater to prevent leaf burn and tip damage from tap water. 🍃 Wipe dusty leaves periodically with a damp cloth to improve light absorption. 🌅 Mist plants in the morning only to avoid keeping leaves wet overnight. 🪴 Keep potting mix consistently evenly moist but not constantly soggy. ✂️ Prune back overlong fronds at their base to encourage full, fresh growth. 🔄 Rotate the pot occasionally to ensure all sides receive adequate light exposure. 💦 Keep humidity tray reservoirs filled to promote evaporation. 🌿 Apply worm castings as a gentle fertilizer that won’t burn delicate roots. ♻️ Repot before plants become severely root bound to stimulate growth. 🌱 Propagate by division every few years to rejuvenate congested specimens.

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