Asplenium scolopendrium aka Hart's Tongue Fern

Hart's tongue fern requires consistent moisture and should be watered when the top 1-2 inches of soil begins to dry out. During the growing season, water once per week, ensuring the potting mixture is moist throughout but not waterlogged. In winter, reduce watering frequency to once every 2 weeks. The fern is sensitive to overwatering, which can cause root rot, so ensure good drainage while maintaining consistent moisture levels.

This fern thrives in bright indirect light to full shade, preferring partial shade with no more than 3 hours of direct sunlight per day. Ideal conditions include 4-6 hours of bright, indirect, filtered light daily. Direct sunlight will scorch and yellow the fronds. Indoors, place near a north, east, or west-facing window. Outdoors, plant in deeply shaded locations such as under leafy tree canopies or in woodland settings.

The ideal temperature range is 50-65°F (10-18°C). This fern demonstrates exceptional cold hardiness, tolerating temperatures down to -30°C (-22°F) and surviving occasional frost. However, it performs poorly in hot climates and is not suitable where summer temperatures regularly exceed 90°F (32°C). When grown outdoors in USDA zones 4-5, it may benefit from frost protection during severe winter weather, though established plants are generally frost hardy to -20°F.

This fern prefers high humidity levels of at least 70%. When humidity is low, the foliage becomes dull and develops crispy brown edges. In warm positions above 64°F (18°C), stand plants on trays of damp pebbles to increase local humidity. Indoors, placing the fern next to a humidifier or grouping it with other plants helps maintain adequate moisture. Regular misting can supplement humidity, though it's less effective than other methods.

Hart's tongue fern propagates via spores or division. For spore propagation, collect ripe spores from the underside of fronds between July and October, then sow immediately on sterilized, humus-rich soil at 15°C. Cover with plastic to maintain moisture; germination occurs in 1-3 months. Division is simpler: carefully separate the plant in spring, ensuring each section has roots and fronds. The spore method is tedious and slow-growing, while division provides faster results for established plants.

Repot your hart's tongue fern each time it doubles in size, typically every 2-3 years for mature plants. Choose a pot only slightly larger than the current one, as ferns prefer being slightly pot-bound. Use humus-rich, well-draining soil that retains moisture. The best time to repot is in spring when the plant is actively growing. After repotting, water thoroughly and keep the fern in a shaded location until it establishes in its new container.

Gently wipe the glossy fronds with a soft, damp cloth to remove dust accumulation, which can block light and reduce photosynthesis. Avoid using leaf shine products, as these can damage the natural waxy coating. For stubborn dirt, use lukewarm water without soap. Handle the fronds carefully as they can be brittle. Regular dusting every few weeks helps maintain the fern's attractive appearance and health.

Yes, hart's tongue fern grows excellently outdoors in USDA hardiness zones 4-9 (UK zone H6). Plant in deeply shaded areas under leafy tree canopies or in woodland gardens with fertile, humus-rich, slightly alkaline limestone soil. It thrives in moist, shady locations such as cave entrances, wooded limestone ravines, north-facing slopes, and alongside water features. Once established, it tolerates dry shade and occasional frost, making it ideal for shaded borders, cottage gardens, and as ground cover.

As an evergreen fern, hart's tongue maintains its fronds year-round with modest seasonal adjustments. During spring and summer (growing season), water weekly and fertilize monthly. In fall and winter, reduce watering to every 2 weeks and withhold fertilizer as growth slows. Remove dead or damaged fronds in spring as new growth emerges. Outdoor plants benefit from annual mulching in spring to retain moisture. The fern requires no dormancy period and continues slow growth throughout winter in suitable conditions.

Hart's tongue fern is generally pest-free outdoors but may attract aphids (greenfly and blackfly), scale insects, slugs, snails, capsids, and vine weevil grubs when grown indoors or in greenhouses. These sap-sucking pests weaken plants and stunt growth. Diseases include root rot in poorly drained soils and crown rot when the crown stays wet in cold conditions. Rust may develop in mild, damp winters. The fern may be sensitive to fungicides, so cultural controls like improved drainage and air circulation are preferred over chemical treatments.

Several ornamental cultivar groups exist: the Crispum Group features deeply frilled, wavy frond margins (including 'Crispum Bolton's Nobile' and 'Crispum Moly'); the Cristatum Group displays crested frond tips with a prehistoric appearance; and the Undulatum Group has ruffled edges. Combined forms include Undulatum Cristatum Group and Crispum Cristatum Group. Other named cultivars include 'Angustatum' (narrow fronds), 'Kaye's Splendour', 'Kirkby Lonsdale', and 'Furcatum' (Forked Hart's Tongue). These varieties maintain the species' care requirements while offering diverse frond textures.

Yellow leaves on hart's tongue fern most commonly result from excessive light exposure. Direct sunlight or more than 3 hours of bright light daily causes yellowing and eventual burning of fronds. Other causes include overwatering leading to root rot, nutrient deficiencies (particularly nitrogen), or natural aging of older fronds. Move the plant to a shadier location with bright indirect light only. Check soil moisture and drainage, allowing the top inch to dry between waterings. Remove yellowed fronds and fertilize monthly during the growing season if nutrient deficiency is suspected.

Brown, crispy leaf edges on hart's tongue fern indicate low humidity levels below the preferred 70%. Too much direct sunlight also causes brown scorching and burning. Inconsistent watering, allowing soil to dry out completely, can result in brown, brittle fronds. To remedy, increase humidity by placing the pot on pebble trays, using a humidifier, or grouping with other plants. Ensure the plant receives only filtered, indirect light and maintain consistent soil moisture. Remove severely damaged brown fronds, and new growth should emerge healthy if conditions improve.

Hart's tongue fern requires minimal pruning. Simply remove dead or damaged fronds as necessary throughout the year by cutting them at the base with clean, sharp scissors or pruning shears. The best time for maintenance pruning is spring before new growth emerges. Avoid cutting healthy green fronds, as this reduces the plant's photosynthetic capacity. The evergreen nature means fronds persist year-round, so only remove those that are brown, crispy, or obviously damaged. Regular tidying in spring keeps the plant looking its best.

Historically, hart's tongue fern was used in traditional medicine with a medicinal rating of 2 out of 5. The fronds possess astringent, diuretic, expectorant, and vulnerary properties. Internally, it treated diarrhea, dysentery, urinary tract diseases, and liver and spleen obstructions. Externally, it was applied as an ointment for piles, burns, and scalds. It was also used for digestive disorders, high blood pressure, and wound healing. However, many ferns contain thiaminase and potential carcinogens, so modern use requires caution and professional guidance.

Beyond ornamental value, hart's tongue fern serves as excellent ground cover for shady positions in gardens, rated 3 out of 5 for other uses. It has traditional cosmetic applications in hair washes and face packs, harvested from the wild for local use as a hair conditioner. Its tolerance of dry shade once established makes it useful in challenging garden spots where other plants struggle.

Hart's Tongue Fern is a low-maintenance plant that requires minimal attention, making it an excellent choice for beginners.

New growth will sprout from the top of the plant as it grows upwards.

Hart's Tongue Fern’s native range is Worldwide.

When growing Hart's Tongue Fern, it is important to pay attention to the soil type you are using. This plant is very sensitive to dry soil and needs a potting soil that retains moisture. A good soil should still be well-draining and contain lots of organic matter. Coco coir or sphagnum moss are great options to provide the Hart's Tongue Fern with the nutrients and moisture it needs. The added organic matter will also help the soil retain water and prevent the Hart's Tongue Fern from drying out too quickly. Before planting, make sure to mix compost or manure into the soil for extra nutrients. Also, make sure to water the Hart's Tongue Fern regularly, making sure to keep the soil evenly moist but never soggy. With the correct soil and watering regimen, the Hart's Tongue Fern will thrive and bring lots of beauty to your home.

The growth of Hart's Tongue Fern is not rapid and it doesn't necessitate any extra fertilization. By replacing its potting soil once a year, it should receive ample nutrition. It is important to note that plants obtain their energy from the sun's rays, not from fertilizers.

Ploi's records do not contain confirmed information on the toxicity of this particular plant. In the event of accidental ingestion of plant material with questionable toxicity by you, a family member, or a pet, it is always a good idea to consult a healthcare professional.