Krauss's Spikemoss - Care Sheet

Overview

Krauss's Spikemoss (Selaginella kraussiana) forms a soft carpet of branching stems and tiny, scale-like leaves. Despite its mossy appearance, it is a vascular, spore-producing plant rather than a true moss or fern. Its creeping stems root as they spread, making it especially attractive in shallow pots and terrariums.

Consider it an intermediate-care houseplant: keeping moisture and humidity steady takes attention. The numerical targets below are practical indoor starting points, rather than strict species limits. A sheltered, humid growing space makes care much easier.

Quick Facts

Light

Choose a bright position with filtered daylight. An east- or north-facing window often works; use a sheer curtain where sunlight is strong. Outdoor shade tolerance does not mean it will thrive in a dark indoor corner. Keep terrariums out of direct sun, which can scorch foliage and rapidly overheat the enclosure.

Water

Keep the mix evenly moist. Check the surface frequently and water as it starts to lose moisture, before the root ball dries. Use room-temperature water, wet the mix thoroughly, and let excess drain away. Empty the saucer or decorative outer pot afterward.

Water according to conditions rather than a weekly timetable. Small pots can dry quickly, while enclosed terrariums need much less added water. In containers without drainage, add small amounts carefully: there should be no standing water around the roots.

Humidity

This plant needs humid air as well as moist soil. Around 60% relative humidity or higher is a useful starting target, adjusted according to foliage condition. A humidifier or terrarium is more dependable than occasional misting. A regularly used bathroom can suit it if there is adequate daylight.

Maintain gentle air circulation. If an enclosure stays heavily condensed and foliage remains wet, ventilate briefly and remove dead material.

Temperature

For everyday indoor care, aim for roughly 18–24°C / 65–75°F. Avoid radiators, heating vents, cold drafts and contact with chilly window glass. The species can tolerate cooler protected conditions: horticultural guidance gives a winter minimum of 5–7°C / 41–45°F under glass. Treat that as a lower limit, not an indoor target, and prevent freezing.

Soil & Potting

Use a mix that holds moisture while allowing excess water to escape. A horticultural recipe is two parts peat-free, loam-based potting compost to one part leafmould. Avoid dense, compacted soil and very coarse mixes that dry rapidly.

A shallow container suits the root system. Choose drainage holes and keep the plant at its previous planting depth. Do not bury the leafy stems or add a gravel layer beneath the compost as a substitute for drainage.

Feeding

Feed conservatively while fresh growth is appearing, usually in spring and summer. A balanced liquid houseplant fertilizer at quarter to half label strength about once a month is a cautious starting routine. Apply to moist compost and follow any product restrictions.

Skip feeding when growth slows or the plant is stressed. Fresh compost may already contain nutrients, so check the packaging before adding more.

Repotting

Inspect in spring each year. Repot when roots crowd the container, moisture becomes difficult to maintain, or the compost compacts; approximately every 1–2 years is a planning guide rather than a deadline. Choose a slightly wider shallow pot, or divide the plant to retain its current size. Handle the delicate mat gently and water afterward.

Propagation

Division is straightforward. In spring, separate a healthy clump into sections, each with roots and leafy stems, then pot into moist mix. Keep divisions humid and out of direct sun while they establish.

Alternatively, lay healthy stem cuttings against damp compost and secure them gently. Rooted creeping sections establish particularly easily. Spore propagation is possible, but division and cuttings are more practical at home.

Common Problems

Brown, crispy foliage

Check for dry compost, low humidity or nearby heating. Restore steady moisture and improve humidity. Trim dead growth; completely browned foliage will not turn green again.

Yellowing, soft stems or wilting in wet soil

Suspect waterlogging and damaged roots. Empty standing water and inspect drainage. Remove rotten tissue and repot surviving healthy sections into fresh mix if necessary.

Bleached or scorched patches

Move the plant away from direct sunlight. Check whether a glass enclosure is overheating, and provide filtered light.

Brown tips after feeding

Excess fertilizer salts may contribute. Stop feeding temporarily and flush a freely draining pot with plain water, allowing it to drain completely.

Toxicity & Pet Safety

The ASPCA lists Selaginella kraussiana as non-toxic to cats, dogs and horses. This species-specific listing should not be extended automatically to every spikemoss, fern-like plant or plant sold as “Irish moss.” Safety for birds, reptiles and small mammals is not established by that listing.

Discourage chewing: even non-toxic plant material can upset digestion, and compost or care products pose separate concerns.

Seasonal Care

During warmer, brighter months, check moisture more often and feed only while growth is active. In winter, watering may become less frequent, but keep the root ball moist. Heating can dry the air even when compost stays damp. Reduce feeding, maintain humidity and move the plant away from cold glass.

Quick Tips

• Provide bright, filtered daylight.
• Check moisture frequently; avoid complete drying.
• Drain thoroughly after watering.
• Use a humidifier or suitable terrarium.
• Choose a shallow pot with drainage holes.
• Feed lightly during active growth.
• Save healthy rooted trimmings for propagation.