Golden Pothos
Epipremnum aureum
Toxic to pets
Button Fern
Pellaea rotundifolia · Pteridaceae
Moderate
Pet-safe
Pellaea rotundifolia is a compact, low-growing fern native to New Zealand and parts of Australia, where it grows on rocky outcrops, cliff faces, and forest margins. Unlike most ferns, it tolerates lower humidity than many of its relatives, making it somewhat more adaptable to typical home environments. Its distinctive arching fronds carry rows of small, leathery, dark green rounded pinnae on dark, wiry stems.
☀ Light
Bright indirect light; tolerates moderate shade
💧 Water
Keep evenly moist but never waterlogged
🌡 Temp
10-24 C
💦 Humidity
Moderate; 40-60% preferred
🌿 Soil
Free-draining, humus-rich mix
🍽 Feeding
Half-strength liquid fertiliser monthly in growing season
Photo: Daderot / Public domain via Wikimedia Commons
How to care for Button Fern
Light
Button fern thrives in bright, indirect light and will tolerate moderate shade, making it suitable for positions a little distance from a window. Direct summer sun will scorch the foliage, causing the pinnae to yellow and crisp at the edges. A north or east-facing windowsill, or a spot a metre or two from a south-facing window, is generally ideal. Consistent light levels are preferred over fluctuating conditions.
Watering
Water when the top centimetre of compost feels dry to the touch, aiming to keep the root zone evenly moist throughout the growing season. Pellaea rotundifolia is more drought-tolerant than many ferns owing to its leathery foliage, but prolonged dryness will cause frond tips to brown and pinnae to drop. Reduce watering in winter when growth slows, but never allow the compost to dry out completely. Always use room-temperature water, and avoid letting the pot sit in standing water.
Soil and potting
A free-draining, moisture-retentive compost suits this species best. A mix of two parts peat-free multipurpose compost, one part perlite, and one part fine bark or leaf mould is suitable. Good drainage is essential to prevent root rot, which this fern is susceptible to if the roots remain waterlogged. A slightly acidic to neutral pH of around 5.5 to 7.0 is appropriate.
Feeding
Feed with a balanced, water-soluble fertiliser diluted to half the recommended strength once a month during the growing season from spring through to early autumn. Avoid feeding in winter when the plant is not actively growing, as excess fertiliser salts can build up in the compost and damage roots. Over-fertilising can cause leaf tip burn and salt accumulation, so it is better to err on the side of caution.
Humidity and temperature
Button fern prefers moderate humidity of around 40 to 60 percent, which is more achievable in an average home than the high humidity required by many tropical ferns. It will tolerate average household humidity but benefits from occasional misting or placement on a shallow tray of damp pebbles, provided the pot base does not sit in water. Temperatures between 10 and 24 degrees Celsius suit the plant well; it can tolerate brief dips close to 5 degrees Celsius but should not be exposed to frost. Avoid positioning the plant near radiators, draughts, or air-conditioning vents, as all three cause rapid moisture loss from the foliage.
Repotting
Repot in spring when roots begin to emerge from the drainage holes or when the plant appears congested in its container. Move up only one pot size at a time, typically to a pot 2 to 3 centimetres wider in diameter. Pellaea rotundifolia grows relatively slowly and does not need frequent repotting; every two to three years is usually sufficient. Shallow, wide pots suit its spreading root system better than deep ones.
Pruning
Remove any dead, yellowing, or damaged fronds by cutting them cleanly at the base with clean scissors or secateurs. Regular removal of old fronds keeps the plant tidy and encourages the development of fresh growth. Do not cut back healthy green fronds unnecessarily, as the plant does not regenerate in the same way as some other houseplants.
Is Button Fern toxic?
Pets: Non-toxic. Pellaea rotundifolia is listed by the ASPCA as non-toxic to cats and dogs. It is not known to cause harm to other common household pets. However, ingestion of plant material may still cause mild gastrointestinal upset in some animals.
People: Not considered toxic to humans. No significant adverse effects are recorded from handling or accidental ingestion of small quantities, though eating houseplants is not advisable.
People: Not considered toxic to humans. No significant adverse effects are recorded from handling or accidental ingestion of small quantities, though eating houseplants is not advisable.
Common problems
Brown, crispy frond tips
Likely cause: Low humidity, underwatering, or exposure to dry, warm air from heating Fix: Increase ambient humidity, water more consistently, and move the plant away from heat sources. Trim affected tips with clean scissors.
Yellowing lower fronds
Likely cause: Overwatering or waterlogging leading to root rot Fix: Allow the compost to partially dry out, check for root rot by removing the plant from its pot, trim any brown mushy roots, and repot into fresh, free-draining compost.
Pale or bleached foliage
Likely cause: Too much direct sunlight Fix: Move the plant to a position with bright but indirect light, shielded from direct sun, particularly during summer.
Dropping pinnae and wilting fronds
Likely cause: Severe underwatering or prolonged drought stress Fix: Water thoroughly until moisture drains from the base, then allow excess to drain away. Maintain more consistent watering going forward.
Small insects on fronds or sticky residue
Likely cause: Infestation by scale insects or mealybugs Fix: Remove visible pests by hand with a cotton bud dipped in isopropyl alcohol; treat with a suitable insecticidal soap or neem oil spray, repeating every week or two until the infestation is resolved.
Slow growth and pale colouring during growing season
Likely cause: Nutrient deficiency due to insufficient feeding or depleted compost Fix: Begin a monthly feeding programme with a balanced liquid fertiliser at half strength, or repot into fresh compost if the plant has not been repotted for several years.
How to propagate
Division
When repotting in spring, carefully separate the rhizome clumps into two or more sections, each with several fronds and a healthy portion of roots. Pot each division into fresh compost and keep warm and moist until established.
Spores
Collect ripe spores from the undersides of mature fronds and sow onto the surface of moist, sterile compost in a covered propagator. Place in a warm, shaded position and maintain high humidity; germination and development of prothalli and then young ferns can take several months.
Where Button Fern comes from
Native to New Zealand, Norfolk Island.
Story and origins
The genus name Pellaea comes from the Greek word 'pellos', meaning dark or dusky, a reference to the characteristically dark-coloured stems that are typical of species in this group. The species epithet rotundifolia is derived from the Latin 'rotundus' (round) and 'folium' (leaf), describing the small, rounded pinnae that give the plant its common name of button fern. The combination of these names therefore effectively describes a fern with dark stems and round leaves.
Pellaea rotundifolia was formally described by the British botanist Joseph Dalton Hooker in the nineteenth century, following collections made during botanical surveys of New Zealand and its associated islands. The species attracted the interest of Victorian fern enthusiasts during the era of pteridomania, a widespread craze for collecting and cultivating ferns that swept Britain in the mid-to-late 1800s. Its relatively compact size and tolerance of indoor conditions made it one of the more accessible fern species for amateur growers of that period. In Maori culture, native ferns held practical and symbolic significance, though button fern was less widely used than the larger, more prominent species such as Cyathea and Dicksonia tree ferns.
Varieties to know
Pellaea rotundifolia (species type)
The standard species is the most widely cultivated form and the one most commonly available in the UK houseplant trade.
Fun facts
- Despite being classified as a fern, Pellaea rotundifolia is considerably more drought-tolerant than most ferns because its leathery pinnae reduce water loss through the leaf surface.
- In its native New Zealand habitat, button fern is often found growing in rock crevices and on steep cliff faces, anchoring itself in very thin, gritty soil.
- The dark, wiry stems of Pellaea rotundifolia have a natural shine and contain a tough, fibrous structure that gives them their characteristic appearance.
- Button fern reproduces in the wild via spores produced in sori on the undersides of mature pinnae, which are covered by the curled-over margin of the frond rather than by a separate membrane (indusium).
- The genus Pellaea is unusual within ferns for containing species adapted to arid and semi-arid habitats, setting them apart from the moisture-loving majority of the fern family.
Button Fern FAQ
Why are the tips of my button fern turning brown?
Brown frond tips are most commonly caused by low humidity or inconsistent watering. Ensure the plant is not near a radiator or draughty window, water before the compost dries out completely, and consider placing the pot on a pebble tray with water to raise humidity around the plant.
How often should I water my button fern?
Water when the top centimetre of compost feels dry, which in average household conditions is typically every five to seven days in summer and every ten to fourteen days in winter. Always check the compost rather than watering on a rigid schedule, as conditions vary considerably between homes.
Can button fern tolerate low light conditions?
It will tolerate moderate to low indirect light, but growth will be slower and the foliage may become a slightly lighter green. It does not cope well with deep shade or very dark corners. A position a metre or two from a bright window, or on a north-facing windowsill, is generally adequate.
Is button fern safe to keep if I have cats or dogs?
Yes, Pellaea rotundifolia is listed by the ASPCA as non-toxic to cats and dogs. While it is reassuring that it is not considered toxic, it is still sensible to discourage pets from chewing on houseplants, as ingesting plant material can occasionally cause mild stomach upsets.
My button fern is losing a lot of pinnae. What is wrong?
Mass dropping of pinnae is usually a sign of significant drought stress, a sudden change in conditions such as a cold draught, or occasionally severe overwatering. Check the compost moisture level, review the plant's position, and address the most likely cause. The plant can recover if the problem is corrected promptly.
Does button fern need misting?
Occasional misting can help during very dry spells, particularly in centrally heated homes in winter, but it is not strictly necessary. A better long-term solution is to place the pot on a shallow tray of damp pebbles or to use a small humidifier nearby, as misting provides only a brief and localised increase in humidity.
How do I propagate button fern?
The most reliable method for home growers is division at repotting time in spring. Carefully separate the rhizome into sections, each with fronds and roots attached, and pot them individually into fresh compost. Propagation by spores is possible but slow and more technically demanding.
