Selaginella kraussiana, sold in most garden centers as Krauss’s clubmoss or spikemoss, is a low-growing groundcover native to the forest floors of Africa. It looks like moss and spreads into dense mats, but it belongs to the same ancient plant family as ferns. The plant earns its reputation as an easy houseplant because it asks for three things only: shade, steady moisture, and soil rich in organic matter. That modest wish list makes it a dependable choice for terrariums, dish gardens, and shaded porches.
Gardeners who want a forgiving first project can pair this groundcover with other straightforward shrubs. The planting, pruning, and seasonal care lessons behind how to grow and care for daphne shrubs apply to many shade-loving plants, and spikemoss is among the easiest of them. Once the basics are in place, the plant grows quickly and rewards consistent watering with a soft, carpet-like appearance.
What Selaginella Kraussiana Needs to Thrive
In its native habitat, selaginella kraussiana covers shady forest floors where humidity stays high and direct sun rarely reaches the ground. Recreate those conditions at home and the plant performs with almost no fuss. Give it low to medium indirect light, plant it in soil that holds moisture, and water often enough that the root zone never dries out completely. Owners who follow those three rules report few problems beyond the occasional browning after a missed watering. The plant also forgives a short dry spell better than most moisture lovers, which makes it a good match for busy schedules.
A Groundcover That Grows Like Moss
The plant stays 2 to 4 inches tall and spreads 12 to 18 inches wide, forming a dense mat as creeping stems root wherever they touch moist soil. The finely branched fronds resemble moss at a glance, but the plant reproduces with spores like its fern relatives instead of flowers or seeds. Gardeners use it as a living carpet between stepping stones, as a filler under taller container plants, and as the base layer inside a closed terrarium. Because it stays so low, it never blocks the plants around it and needs no trimming to hold its shape.
Hardiness and Climate Limits
Outdoors, selaginella kraussiana is reliably hardy only in USDA zones 11 and 12, which limits it to frost-free regions such as South Florida and Hawaii. Everywhere else it grows as a houseplant or as a seasonal groundcover that is replaced each spring. Because it cannot survive freezing temperatures, most owners keep it indoors or in a greenhouse where winter lows stay above 40 degrees F.
| Factor | What the plant needs |
|---|---|
| Light | Low to medium indirect light |
| Soil | Moist loam or clay with high organic matter |
| Water | Evenly moist; never soggy, never bone dry |
| Humidity | High; 50 percent or more is ideal |
| Mature size | 2 to 4 inches tall, 12 to 18 inches wide |
| Hardiness | USDA zones 11 and 12 outdoors |
Gardeners who already grow shade-loving shrubs will recognize the care pattern explained in how to grow and care for azaleas: shelter from harsh sun, organic soil, and steady moisture through the growing season. If those conditions describe your garden, spikemoss will feel like an easy addition rather than a demanding one.
Light, Soil, and Planting Setup
Two decisions shape most of the outcome with this plant: where the light comes from and what the roots sit in. Both are easy to get right once you understand what the plant evolved to tolerate.
Light Requirements: Low to Medium Indirect Light
Place the plant where it receives bright but indirect light for most of the day. A north-facing window, a spot several feet back from an east window, or the shaded side of a covered patio all work well. Direct sunlight scorches the fronds, turning them brown and crispy within days. Fluorescent and LED grow lights also satisfy the plant when natural light is limited, which makes it a strong candidate for offices and windowless bathrooms.
Signs of Too Much Sun
Watch for bleached, yellowed, or papery fronds. When the outer edges of the mat turn brown while the center stays green, the plant is receiving more light than it wants. Move it to a shadier position and trim the damaged fronds; new growth usually appears within a few weeks.
Soil That Holds Moisture
Selaginella kraussiana grows naturally in moist loamy or clay soils rich in organic matter. A standard houseplant potting mix amended with peat moss or coconut coir reproduces that water-holding behavior in containers. Aim for a pH between 5.0 and 6.5, mildly acidic to neutral, which matches the forest-floor soil the plant comes from.
Planting in a Pot or Terrarium
- Choose a pot with drainage holes, or a terrarium with a gravel drainage layer at the base.
- Fill with a peat-and-coir potting mix and moisten it before planting.
- Set the plant so the crown sits at soil level, then firm the mix around the roots.
- Water thoroughly and keep the container in indirect light for the first week.
Where the plant lives matters for the long term, especially for homeowners who expect to stay put. The same forward planning that leads families to weigh residential care costs against age-proofing your current home applies to plant placement: put moisture-loving plants where the soil is easy to reach, where watering spills will not damage flooring, and where the humidity from a bathroom or kitchen gives the plants a free boost.
Watering, Humidity, and Feeding
Water is the single most important input for this plant. The soil should stay evenly moist, like a wrung-out sponge, but never waterlogged. Letting the root ball dry out completely stresses the plant and browns the frond tips; leaving the pot sitting in standing water invites root rot. Consistency matters more than volume: a steady supply of moisture beats occasional heavy soakings.
In practice, most plants need water every two to three days in summer and every four to seven days in winter, but the only reliable schedule is the one the soil dictates. Check by touch: if the top half-inch feels dry, water. A closed terrarium may go two weeks or more between waterings because condensation recycles moisture.
Tools That Take the Guesswork Out of Watering
A few inexpensive tools keep watering consistent. A moisture meter with a metal probe reports soil moisture at root depth, a spray bottle delivers the fine mist the fronds enjoy, and a tray of wet pebbles under the pot raises local humidity. Grow-light timers, humidifiers, and rechargeable misters all depend on batteries, and the truth about cordless power tool battery care holds for them too: modern lithium packs last longest with partial charges, cool storage, and protection from deep discharge.
Fertilizer: Twice a Year Is Enough
Feed the plant twice a year during the active growing season, once in spring and once in early summer. Use a balanced liquid houseplant fertilizer diluted to half the label strength. Skip feeding in fall and winter, when growth slows and unused salts can build up in the soil.
Water Quality and Temperature
Room-temperature water works best. Cold water straight from the tap shocks the roots, and softened water adds salts that accumulate over time. Keep the plant away from heating vents and air conditioner drafts, which dry the air faster than the plant can recover.
Troubleshooting and Reviving a Struggling Plant
Most spikemoss problems trace back to water, light, or pests. Diagnose before acting: a plant that looks the same after watering has a different issue than one that perks up within hours.
Common Problems and Quick Fixes
| Symptom | Likely cause | Fix |
|---|---|---|
| Brown, crispy fronds | Direct sun or dry air | Move to shade; raise humidity |
| Yellowing fronds | Overwatering | Let soil dry slightly; improve drainage |
| Wilting after watering | Root rot | Repot in fresh mix; trim dead roots |
| Pale, leggy growth | Too little light | Move closer to a bright window |
| Fine webbing on fronds | Spider mites | Rinse; treat with insecticidal soap |
Reviving a Dried-Out Plant
A completely dried-out mat can still come back if the roots survived. Cut away the dead brown growth, soak the root ball in room-temperature water for 20 minutes, and set the pot in a shady, humid spot. New green shoots often appear at the base within two to three weeks. Working in stages mirrors the approach used when restoring cracked and weathered decking: remove the damaged material first, address the underlying cause, then let the healthy parts recover at their own pace.
Propagation and Seasonal Maintenance
Because the plant roots so readily, one healthy mat can become several. Propagation takes minutes, and a simple seasonal routine keeps the plant dense and green year-round. Set the cuttings up in spring or early summer, when growth is fastest, and they root without special equipment.
Propagating From Stem Cuttings
- Snip a 2- to 3-inch stem tip with clean scissors.
- Remove the lowest leaves and press the stem into moist potting mix.
- Keep the cutting inside a sealed plastic bag or under a glass cloche to hold humidity.
- Move the new plant to normal room conditions once roots form, usually in two to four weeks.
- Pot several cuttings together for a fuller, denser display.
A Seasonal Care Calendar
Spikemoss grows fastest in spring and summer and slows noticeably in winter. Adjust watering as the growth rate changes: water more often and feed in the warm months, then cut back to light watering and no fertilizer when growth stalls.
- Spring: repot if roots fill the container, begin feeding, and start new cuttings.
- Summer: water frequently, mist daily, and keep the plant out of direct sun.
- Fall: reduce watering, stop fertilizer, and check for pests before moving plants indoors.
- Winter: raise humidity, water sparingly, and skip feeding until growth resumes.
Winter Care Indoors
Winter indoor air is dry, so humidity matters more than ever. Group plants together, run a small humidifier, or set pots on pebble trays. Before storing watering gear and lighting equipment for the season, review cold weather tools care so misters, timers, and hoses come out working next spring.
A healthy spikemoss in a dish garden looks at home on natural surfaces, and a wood countertop selection chosen for humid rooms keeps the display area as sound as the plant itself. With shade, moisture, and a twice-yearly feed, this small groundcover stays green for years, whether it carpets a terrarium floor or fills a shaded corner of the garden.