Spikemoss care guide

Spikemoss is a low, soft carpet of tiny, scale-like leaves. It looks like a moss or a tiny fern, but it is neither. It belongs to an ancient group of plants older than ferns. It needs moist soil and moist air. In a dry room, it crisps up fast. In a terrarium, it thrives.

Light

Give it medium to bright indirect light. An east or north window is ideal. In a terrarium, keep it out of direct sun, or the glass will cook it.

Direct sun bleaches and burns it. In low light, it grows thin and pale.

Water

Keep the soil moist at all times. Never let it dry out. Even one dry spell can brown large patches.

Water when the surface just starts to feel dry. Water until it drains, then empty the saucer. Bottom watering works well for this plant. See how to bottom water houseplants step by step.

Moist does not mean soggy. Soggy soil with no air rots the stems.

Soil and potting

Use a moist, peat or coir-based potting mix.

Its roots are shallow. A shallow pot or a terrarium suits it. Repot every year or two in spring. See how to repot a houseplant step by step.

Humidity and temperature

Humidity matters most for spikemoss. It needs 60% or higher. Most homes are drier than that, most of all in winter.

A terrarium is the easiest way to grow it. A closed or half-open glass container holds in moisture. Open the lid now and then to let in fresh air. A humidifier or a bright bathroom can work too, but expect some browning.

Keep it between 16 and 24°C (60 and 75°F), and above 10°C (50°F).

Feeding

Feed monthly in spring and summer with a balanced liquid fertilizer at quarter strength. It needs little food. Skip feeding in fall and winter.

Frosty fern

Frosty fern is a spikemoss with white tips. It is sold at Christmas. The white tips fade to green as it grows. That is normal. Cool, bright conditions help keep some white on new growth.

Pruning

Trim brown patches with small scissors. Trim the edges to keep it in shape. New growth fills in fast in good conditions.

Propagation

Spikemoss roots where its stems touch moist soil. Cut a piece 5 cm (2 in) long and press it onto moist mix. Keep it humid, under a clear lid or bag. Roots form in two to four weeks.

Problems

What you see	Most likely cause
Brown, crispy patches	Dry air, or soil that dried out
Brown, mushy patches	Soggy soil, or a terrarium with no fresh air
Pale, bleached color	Too much direct sun
Thin, sparse growth	Not enough light
Frosty fern tips turn green	Normal as it grows
Tiny flies around the soil	Fungus gnats

Pests

Pests are rare. Spider mites can show up in dry air. Fungus gnats like its moist soil. See how to get rid of fungus gnats in houseplants.

Pet safety

The ASPCA lists spikemoss, Selaginella kraussiana, as non-toxic to cats and dogs.

Varieties

• Spreading spikemoss, Selaginella kraussiana, forms a low, bright green mat. ‘Aurea’ is golden green.
• Selaginella martensii grows more upright, like tiny fern fronds.
• Peacock spikemoss, Selaginella uncinata, has a blue-green shimmer.
• Resurrection plant, Selaginella lepidophylla, is sold as a dry, curled ball that opens in water. Its care is different. It needs to dry out between soaks.