How to grow button fern
Overview
Button fern (Pellaea rotundifolia) is a low-growing, herbaceous fern from New Zealand, prized for its rounded, dark green leaflets on wiry stems. It is grown primarily as a foliage plant for shaded garden beds, rockeries, or containers, and thrives in consistently moist, well-drained conditions with protection from harsh sun.
Soil Preparation
Button fern prefers a slightly acidic to neutral soil (pH 5.5–7.0) that is rich in organic matter and drains well. Amend heavy clay with coarse sand or perlite, and add well-rotted compost or leaf mould to improve moisture retention and aeration.
Growing Guide
Plant button fern in a shaded or part-shaded position with dappled light, avoiding direct afternoon sun. Use a well-draining, humus-rich potting mix or garden soil with added organic matter; space plants 20–30 cm apart. Keep the soil consistently moist but not waterlogged, and apply a thin layer of mulch to retain moisture. In cooler zones, wait until after the last frost to plant out, and protect from cold snaps with a frost cloth or by moving pots under cover.
Care
Feed with a balanced liquid fertiliser (e.g., half-strength every 4–6 weeks) during spring and summer. Remove any brown or damaged fronds at the base to keep the plant tidy. Repot every 2–3 years in fresh, well-draining mix to refresh the soil and prevent root congestion.
Companion Planting
Button fern pairs well with other shade-loving plants such as hostas, hellebores, and Japanese forest grass. Avoid planting near aggressive, sun-loving species like lavender or rosemary, which will outcompete it for light and moisture.
Common Pests & Risks
Scale insects can appear on the fronds, especially in humid conditions; treat with a horticultural oil spray. Fungus gnats may occur in overwatered pots; reduce watering frequency and allow the top layer of soil to dry slightly between waterings.
Troubleshooting
Yellowing fronds: usually from overwatering or poor drainage; allow soil to dry slightly and improve drainage. Brown frond tips: caused by low humidity or dry air; mist regularly or place on a pebble tray. Stunted growth: often from insufficient light; move to a brighter but still shaded spot. Fronds wilting: check for root rot from waterlogging; repot into fresh mix and reduce watering. Scale on stems: treat with neem oil or a soft brush.