How to Care for Button Fern

The Button Fern (Pellaea rotundifolia) is a distinctive small fern with wiry, arching fronds lined by rows of round, leathery, dark green buttons. Unlike many ferns it comes from drier rocky habitats, so it is more tolerant of lower humidity, though keeping it lightly moist and steady takes a moderate touch.

Light

Provide bright indirect light, avoiding direct sun which can scorch the delicate fronds. A spot near an east or north window, or a few feet back from a brighter window, suits it well. It also tolerates moderate shade, though very low light slows growth and can make it sparse.

Water

Keep the soil lightly and evenly moist, watering when the surface just begins to dry. Button Fern is less thirsty than typical ferns and dislikes being waterlogged, so avoid soggy soil that can rot its fine roots. It is also less forgiving of complete dryout than a succulent, so aim for consistent light moisture rather than extremes.

Soil & Potting

Use a well-draining, humus-rich potting mix with added perlite or fine bark for aeration. A slightly gritty mix reflects its rocky native ground. Ensure the pot has drainage holes, since standing water quickly harms the roots.

Humidity & Temperature

Though more drought-hardy than most ferns, Button Fern still prefers moderate humidity and grows best above about 40-50%. Average indoor humidity is usually acceptable, but very dry heated air can brown the fronds. Keep it in comfortable temperatures of about 60-75F and away from cold drafts and hot vents.

Feeding

Feed with a balanced liquid fertilizer diluted to half strength once a month during spring and summer. Ferns are light feeders, so avoid strong doses which can burn the fine roots and scorch frond tips. Stop feeding in fall and winter.

Propagation

Propagate by division in spring: gently separate the clump into sections, each with its own roots and several fronds, and pot them up individually in moist mix. Keep divisions warm and lightly moist until they establish. Spore propagation is possible but slow and rarely done at home.

Repotting / Pruning

Repot every two years or when the plant outgrows its pot, in spring, moving up one size. Pruning is minimal — simply trim away any old, browned, or damaged fronds at the base to keep the plant tidy and encourage fresh growth.

Common Problems & Pests

Browning or crispy fronds usually mean the air is too dry or the soil dried out too much, while yellowing and mushy stems point to overwatering. Keep moisture steady to avoid both. Watch for scale, mealybugs, and spider mites, particularly in dry conditions; treat early with gentle methods like wiping and insecticidal soap.

Seasonal Care Tips

In spring and summer, the fern grows actively — keep it lightly moist, feed monthly, and divide or repot as needed. In fall and winter, growth slows, so reduce watering slightly and hold off on feeding, while guarding against the dry air of indoor heating that can brown the fronds.