Button fern

Button fern: how do you recognise it?

Growth habit

Compact, evergreen fern about 30 cm tall and 40 cm wide, with slightly arching, almost trailing fronds.

Foliage

Each frond is 20–40 cm long and bears two rows of round to oval, leathery leaflets of about 1–2 cm, dark green and slightly glossy.

Stalks

Thin, wiry and dark brown to black: they carry the leaflets like buttons on a string.

Rhizome

Short, creeping rhizome just under or on the surface of the compost: it needs a wide, shallow pot.

Reproduction

No flowers: ferns reproduce by spores formed under the leaves.

Plants: March–April · Pruning: March–April

Why grow it?

• Striking, round leaflets: a very different look from the finely divided fronds of most ferns.
• Tolerates dry indoor air and a missed watering better than most ferns.
• Compact and gracefully arching: lovely in a small hanging pot or in a bowl.
• Evergreen, so attractive all year round.
• Easy to divide and to pass on to friends.

Button fern: where does it grow best?

• Bright light without direct sun or light half shade: an east- or north-facing window, or some distance from a south- or west-facing one. A few hours of gentle morning sun are fine.
• Airy, humus-rich potting compost with a little perlite, free-draining and acid to neutral.
• Room temperature of 15–22 °C. Never below 5 °C.
• It tolerates normal room air; in a dry, heated room a tray of damp clay pebbles helps. Keep it away from draughts and radiators.

Light

Bright, out of direct sun

Potting soil

Multi-purpose compost or airy, humus-rich compost

Acidity

Acid or neutral

Watering

Moderately

Size

0.3 m tall, 0.4 m wide

Temperature

Minimum 5 °C

Goes well with

• Pteris: Another fern that likes the same light shade.
• Peperomia: A compact foliage plant, with the same bright spot and sparing watering.
• Calathea: Beautiful leaf patterns next to the round leaflets, likes the same light.
• Ivy: A green, trailing contrast in a bright room.

Button fern: when and how to plant it?

Plant in March–April.

1. Repot in March–April, about every 2 years or as soon as the roots fill the pot.
2. Choose a wide, shallow pot with drainage holes, one size larger than the last: the rhizome spreads mostly sideways.
3. Use airy potting compost with a fifth of perlite or fine bark so that water drains well.
4. Set the plant at the same depth as before and do not bury the rhizome too deeply; firm the compost gently.
5. Water lightly and then let the top layer dry out a little. Keep it out of strong sun for the first few weeks.

Care

Water

Keep the compost lightly moist but never wet: let the top 1–2 cm dry out between waterings. Water at the edge and empty excess water from the saucer. Drying out quickly causes brown, falling leaflets.

Feeding

From March to September every 4 weeks, half a dose of liquid houseplant feed. Not in winter.

Humidity

Normal room air is enough, but in a dry, heated room a tray of damp clay pebbles or an occasional mist helps.

Light

Turn the pot now and then so that it grows evenly and does not lean towards the window.

Tidying

Cut dried-up stalks off at the base to keep the plant looking fresh.

Tip: Keep the compost lightly moist but never wet: unlike many ferns, it tolerates drier air. Grow it in a small hanging pot or bowl in a bright spot without strong sun and cut dried-up stalks off at the base.

Button fern: when to prune it?

Pruning months: March–April.

When: In March–April, just before new growth starts. You can also cut off withered fronds at any time of year.

How:

• Cut brown or withered stalks off right at the base with clean scissors.
• Leave healthy green fronds in place: the plant needs them to grow.
• On a bare or untidy plant you can cut the oldest fronds off at the base in spring; new fronds come from the rhizome.

Caution: Do not cut too much at once: a plant with too few leaves recovers slowly.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April when repotting: cut the rhizome with a clean knife into pieces with at least 2–3 fronds and some roots. Pot each piece separately in moist, airy compost and keep it bright, moist and sheltered for a few weeks.

Spores

Possible but slow: sprinkle spores on moist, sterile compost, cover with glass or plastic and keep warm (20–22 °C) and bright. It takes months before tiny plants appear.

Button fern: how does it get through the winter?

• Not hardy in Belgium: the minimum temperature is 5 °C. It overwinters indoors.
• Keep it bright and cool (12–18 °C) and water slightly less: the top layer may dry out further, but never the whole rootball.
• Keep it away from radiators and draughts: the leaflets otherwise dry out quickly and drop.
• Do not feed from October to February inclusive.

Diseases and pests

• Falling leaflets: Caused by dry compost, draughts or hot, dry air. Check the moisture in the pot and move it away from draughts and heating. Fallen leaflets do not come back, but new growth does.
• Yellow or brown fronds: Usually too wet (root rot) or too much sun. Let the top layer dry out, make sure the pot drains and cut off affected fronds.
• Scale insects and mealybugs: Small brown shields or white fluffy patches on the stalks. Wipe them off with a cotton bud dipped in a little soapy water and repeat weekly; ferns are sensitive to many sprays.
• Fungus gnats: Small black flies above the compost when it is too wet. Let the top layer dry out and hang up yellow sticky traps.

Through the year

• January: Rest: bright and cool, water moderately, do not feed.
• February: Rest. Keep an eye on dry air from heating.
• March: Cut off old fronds. Repot or divide.
• April: Repotting or dividing still possible. Start feeding (half dose).
• May: Growing season: water regularly, shade from strong sun.
• June: Growth. Feed every 4 weeks.
• July: Growth. Watch for drying out in hot weather.
• August: Growth. Feed every 4 weeks.
• September: Last feed. Check for pests.
• October: Water less. Stop feeding.
• November: Rest: bright and cool.
• December: Rest. Keep away from radiators.

Did you know?

• The name Pellaea comes from the Greek pellos, ‘dark’, referring to the dark stalks.
• Its English name is button fern: the round leaflets look like buttons on a string.
• Ferns have neither flowers nor seeds: they reproduce by spores formed under or at the edge of the leaves.