Why Are My Davallia Fronds Curling?

Low humidity

Low humidity is the most common cause of davallia frond curl in UK indoor conditions. The finely divided, lacy fronds have a large surface area relative to their mass and lose moisture rapidly to dry air. Central heating in winter drives ambient humidity in UK homes below 40 percent, causing the frond segments to curl and the frond tips to brown progressively. The exposed surface rhizomes, which absorb moisture from the air as well as from the potting mix, also deteriorate in persistently dry conditions, becoming dry and slightly shrivelled rather than plump and fleshy.

What to do

• Position davallia in a bathroom, kitchen, or conservatory where ambient humidity is naturally higher than in centrally heated living rooms. The combination of indirect light and higher humidity in a regularly used bathroom is close to ideal for davallia.
• Mist the rhizomes and fronds regularly in dry conditions, using room-temperature water. The rhizomes absorb moisture directly from misting and benefit from being kept lightly damp even when the potting mix is in its drying phase between waterings.
• Use a room humidifier near the plant in winter, or place it on a pebble tray with water to maintain local humidity through evaporation.
• Keep davallia away from radiators, underfloor heating, and draughts from exterior doors and windows, all of which significantly lower the local humidity around the plant.

Underwatering

Underwatering causes davallia fronds to curl inward and progressively yellow and brown from the tips. Because davallia is often grown in bark-based, free-draining epiphytic mixes that dry faster than conventional compost, underwatering is easy to cause by following a watering schedule designed for soil-based houseplants. The exposed surface rhizomes also dry and begin to shrivel when the plant is underwatered, providing a useful additional visual indicator beyond frond appearance.

What to do

• Check the potting mix regularly by inserting a finger 2 to 3 centimetres into the mix: water when this depth feels barely damp rather than moist. In bark-based mixes, this may mean watering every 5 to 10 days in warm conditions.
• When watering, water thoroughly from above until water drains from the base. Alternatively, soak the entire pot in a bowl of room-temperature water for 15 to 20 minutes, then allow to drain fully before replacing.
• Mist the rhizomes at the same time as watering: they absorb moisture from the surface and keeping them lightly damp helps bridge the gap between waterings.
• Trim any badly crisped frond sections with sharp scissors: this reduces the moisture demand on the remaining healthy fronds and improves the plant's appearance while it recovers.

Overwatering

Overwatering in persistently wet, oxygen-poor potting mix causes the rhizomes and roots of davallia to rot. Unlike the rapid, clear response to underwatering, overwatering shows more gradually: the fronds yellow and weaken before curling, and sections of rhizome become dark, soft, and slimy at the soil surface. Overwatered davallia often shows the highest frond mortality in the oldest, central parts of the plant, where the oldest rhizome sections are most affected by root rot.

What to do

• Use a very free-draining, bark-based epiphytic mix rather than conventional peat or coir compost. Coarse orchid bark with added perlite is ideal, providing excellent drainage and aeration around the rhizomes.
• Never leave davallia sitting in water in a saucer. The exposed rhizomes sitting in standing water at the pot base deteriorate very quickly.
• If rhizome rot is detected, cut away any blackened, soft sections with clean scissors, dust the cuts with powdered cinnamon to reduce further fungal spread, and repot into fresh bark mix in a clean pot.

Direct sun

Direct sunlight scorches and bleaches the delicate, finely divided fronds of davallia rapidly. The fronds are thin-textured with a large surface area and are poorly adapted to direct sun exposure. In bright, indirect light they remain a healthy, rich green; in direct summer sun they bleach, curl, and develop papery brown patches within days. Position davallia carefully away from direct sun while ensuring adequate light for healthy frond development.

What to do

• Place davallia in bright, indirect light. A north- or east-facing window, or a shaded position within a south- or west-facing room, is ideal. Davallia also tolerates moderate shade better than most ferns, though very dim conditions slow growth.
• In hanging basket displays, where davallia is often grown to show off the trailing rhizomes, ensure the basket position receives no direct sun at any time of day in summer. A shaded porch or a position under a pergola or canopy that filters sunlight is ideal.

Cold temperatures

Davallia is tender and does not tolerate temperatures below about 7 to 10 degrees Celsius, depending on species. Cold causes the fronds to yellow and curl, and the rhizomes to become flaccid and unresponsive. In UK conditions, davallia must be kept as a houseplant or in a frost-free greenhouse throughout winter. Brief cold draughts from windows cause localised frond curl and yellowing on the most exposed fronds.

What to do

• Maintain davallia in temperatures above 10 degrees Celsius year-round. Keep it away from cold draughts, cold windowsills, and any exterior walls that become cold at night in winter.
• In very warm rooms in summer, davallia grows vigorously and may need more frequent watering as temperatures increase. Monitor the potting mix more frequently as the weather warms in spring.

Frequently asked questions

Why are my davallia fronds curling?

Davallia fronds curl most often from low humidity or underwatering. Davallia is an epiphytic fern native to tropical and subtropical Asia and the Pacific, where it grows on trees and rocks in humid environments. In UK homes, the combination of low humidity from central heating in winter and the relatively free-draining, bark-based potting mix often recommended for davallia means the plant can dry out faster than gardeners expect. The finely divided, lacy fronds lose moisture readily and curl inward when stressed by either dry air or dry roots.

Why is davallia called rabbit's foot fern?

Davallia is commonly called rabbit's foot fern (or squirrel's foot fern or deer's foot fern, depending on the species) because of its distinctive, fuzzy rhizomes that creep across and over the edge of pots and mounting surfaces, resembling small furry feet or paws. The rhizomes are covered in dense, silvery or brown scales that give them a distinctly animal-like texture. These visible rhizomes are one of the plant's most characterful features and should never be buried: they need to remain on the surface of the potting mix or mount, where they also absorb moisture directly from the air and from misting.

Should I bury the rhizomes of my davallia?

No: the surface rhizomes of davallia should never be buried in potting mix. They naturally grow on the surface of their substrate and over the edges of pots, and burying them causes them to rot and prevents them from absorbing moisture from the air. When potting davallia, place the rhizomes on top of the potting mix rather than beneath it, anchoring them lightly with wire staples if needed to prevent them from lifting away from the surface. The rhizomes can also be misted directly as part of the watering routine, which they absorb effectively.

How do I water davallia correctly?

Water davallia when the top third of the potting mix has dried out, watering thoroughly until water drains from the base of the pot. Because davallia is an epiphyte grown in bark-based, free-draining mix, it dries out faster than conventional houseplants in peat or coir compost, and the watering frequency needs to reflect this. In warm, dry rooms in winter, watering every 7 to 10 days may be needed. Mist the exposed rhizomes at the soil surface or pot edges at the same time as watering, as they absorb moisture directly. Never leave davallia sitting in standing water, which causes rhizome and root rot.