Plant Profile & Key Characteristics
Overview: A low, mat-forming evergreen spikemoss reaching only 5-15 cm (2-6 in) high but spreading to form a mossy, fern-like carpet. This spore-bearing lycophyte is grown purely as an ornamental foliage plant for shady, humid spots, terrariums and as an indoor groundcover.
Quick Specifications
| Specification | Attribute |
|---|---|
| Plant Type / Life Cycle | Herbaceous perennial (spore-bearing lycophyte / fern ally) |
| Foliage Type | Evergreen (can be semi-deciduous in cold) |
| Mature Size | 5-15 cm (2-6 in) tall, spreading indefinitely as a mat |
| Growth Rate | Moderate to fast |
| Root System | Shallow and fibrous, produced from creeping stems (rhizophores) that root as they spread |
| Hardiness | USDA zone 11+ (to 10b with extra care and frost protection) |
Growth Form & Structure
- Height & Spread: Stays 5-15 cm (2-6 in) tall in the ground yet creeps outward to cover a wide area; in a pot it trails over the rim and stays more contained, and is potted up 40-50% larger than the root ball as it fills in.
- Growth Habit & Form: Low, creeping mat-former with slender branching stems clothed in tiny scale-like leaves, giving a soft moss-and-fern texture; it can become invasive in warm, damp sites.
- Lifespan & Maturity: Long-lived perennial that roots freely along its stems and reaches spreading size within a season or two in warm, humid conditions.
Anatomy & Physical Features
- Leaves & Foliage: Bright green, scale-like leaves, often edged white or yellow, densely clothing trailing stems. It bears no true flowers, reproducing by spores.
Primary Uses & Landscape Value
- Functional & Ornamental Roles: Shade- and moisture-loving groundcover, terrarium and bottle-garden filler, and an easy indoor foliage houseplant where humidity is kept high.
Care Guide: Planting, Soil & Watering
Overview: Selaginella kraussiana (spikemoss) is a moisture-loving, shade-dwelling foliage plant that wants high humidity, rich organic soil and steadily moist — but never soggy — conditions. Unlike a succulent it must not be allowed to dry out, yet it still needs good drainage to keep its shallow roots from rotting.
Quick Care Requirements
| Requirement | Ideal Condition |
|---|---|
| Planting Season | Spring to summer in zone 10b (avoiding the hottest days); spring to autumn in zone 11; year-round in zones 12+ |
| Growth Rate | Moderate to Fast |
| Soil Type | Rich, moisture-retentive soil high in organic matter — a peat-based mix with perlite |
| Water Need | Moderate to High — keep the soil constantly moist and never let it dry out |
Planting & Establishment
- Best Planting Season: Plant in spring once the weather is warm and settled, avoiding peak summer heat; it is frost-tender, so in cool climates grow it indoors or in a sheltered, shaded spot.
- How to Plant:
- Hole Preparation: Prepare a hole only a little larger than the small, shallow root ball; spikemoss roots run near the surface and want a moist but well-aerated pocket rather than a deep one.
- Soil Amendments: Work in plenty of compost, leaf mould or peat plus a little perlite so the soil holds moisture yet still drains — rich, spongy, humus-filled ground is ideal.
- Planting Depth: Set it at the depth it grew before, leaving the creeping stems resting on the surface where they root as they spread.
- Growth Speed & Expectations: In warm, humid shade it grows at a moderate to fast pace, spreading into a soft, low carpet of foliage.
Soil, Watering & Drainage Care
- Soil Mix & Drainage Needs: Use a rich, organic, moisture-retentive mix (potting or peat soil with perlite); in pots choose one only 40–50% larger than the root ball with good drainage, so the soil stays evenly damp without turning stagnant.
- Watering Schedule & Technique:
- Young / Newly Planted: Keep the soil evenly moist from the start and never let it dry; mist regularly to give young plants the high humidity they need to establish.
- Established: Water regularly so the soil stays consistently damp — this is not a plant to let dry between waterings — and pair steady moisture with high humidity, especially indoors.
- Seasonal Adjustments: Water a little less in cool winter weather when growth slows, but never let it dry out; increase misting and watering during hot, dry spells.
Climate, Light & Hardiness
Selaginella kraussiana (spikemoss) is a tender, humidity-loving tropical/subtropical groundcover that needs consistent warmth, full shade, and high humidity, commonly grown as a houseplant or terrarium plant outside the tropics. It has essentially no frost tolerance.
Quick Climate Specifications
| Climate Zones | Tropical, Subtropics (Mediterranean with added summer moisture; also grown indoors) |
|---|---|
| USDA Hardiness Zones | 11+ as a perennial; can succeed in zone 10b with the right care |
| Optimal Temp Range | Best above about 15°C (59°F) |
| Approx. Survival Minimum | Can tolerate temperatures down to roughly 7°C (45°F) for brief periods |
| Frost Tolerance | None |
| Light Conditions | Full Shade |
Sunlight & Light Exposure
Optimal Light Setup
Needs full shade; this is a shade-loving groundcover, not a sun plant, and direct sun will scorch the delicate foliage.
Temperature Extremes & Hardiness
USDA Hardiness & Regional Limits
Reliable as a perennial only in zone 11 and warmer, with careful siting allowing success in zone 10b; elsewhere it is grown as a houseplant or terrarium specimen.
Cold Damage & Winter Protection
Growth is best kept above roughly 15°C (59°F); the site notes it can tolerate down to about 7°C (45°F) for a time, but sustained cold below that will stress or kill the plant.
Frost Sensitivity
No frost tolerance – any freezing temperature is likely fatal.
Wind, Humidity & Microclimate
Humidity Preferences
Requires consistently high humidity; indoor growers need to actively maintain moist air (e.g. pebble trays, misting, terrariums).
Dry-Air Tolerance
Poor – dry indoor air is a common cause of decline, so humidity management is essential when grown as a houseplant.
Microclimate Recommendations
In Mediterranean climates it needs supplemental moisture and shade through the summer; a shaded, humid microclimate (or terrarium/greenhouse) gives the most reliable results outside the tropics.
Growing in Pots, Balconies & Indoors
Krauss’s spikemoss (Selaginella kraussiana) is a low, spreading, moss-like ground creeper (5-15 cm) that loves shade and moisture. The grower confirms it makes a fine houseplant as long as indoor humidity is kept up – it is ideal for terrariums, shaded pots and as living groundcover under taller container plants.
Quick Details
- Container Size: A pot 40-50% larger than the root ball (per the grower)
- Indoor Suitability: A good houseplant – keep the air humid indoors
- Best Spot: Full shade; bright, indirect light indoors
- Soil & Drainage: Rich, organic mix (potting or peat soil + perlite) with good drainage
- Watering in Pots: Average to big amount – keep evenly moist, never let it dry out too much
Indoors & On the Windowsill
- A true houseplant: The grower confirms it grows indoors; the key is humidity – a terrarium, grouped pots or occasional misting keep it lush.
- Light: It naturally grows in full shade, so bright indirect light indoors suits it well – keep it out of direct sun.
- Moisture: Never let it dry out too much, but ensure the pot drains so it is not waterlogged.
On a Balcony or Patio
- Light, wind & heat: Give it the brightest spot it will tolerate; walls and railings reflect heat and dry pots quickly, so check moisture often and shelter or stake exposed growth.
- Shade & damp: Outdoors it wants a shaded, humid, sheltered spot; it is not a sun-and-wind balcony plant.
Choosing the Pot, Soil & Long-Term Care
- Pot & drainage: A pot about 40-50% larger than the root ball, as the grower advises. Use strong drainage holes and skip a standing-water saucer to avoid root rot. Terracotta breathes and dries faster; glazed or plastic holds moisture longer.
- Potting mix: A rich, organic mix – potting or peat soil with perlite – kept moist but drained.
- Feeding: Only a small amount of fertiliser is needed, and only every few years.
- Repotting: Pot up when the roots fill the container; once at its final size, change the soil and cut back some roots and shoots every few years.
Grower’s Container Tip
- Grower’s potting routine: Choose a pot 40-50% bigger than the root ball and move up when the roots fill it. At its final size, refresh the soil and trim some roots and leaves every few years, feed only lightly every 3-4 years, and top up with humus and mulch to hold moisture.
Fertilizing & Feeding
A light feeder: this moisture-loving spikemoss is grown purely for its foliage and asks for only a very light, infrequent feeding, with none at all right after a fresh repotting or while humidity and light are low.
Quick Fertilizing Specs
| Feeding Level | Light feeder |
|---|---|
| Main Nutrient Priority | A dilute balanced feeding to support foliage color and density |
| Best Feeding Period | During active growth when warmth and humidity are consistently good |
| Organic Options | Rich, organic, peat-based potting mix renewed at repotting |
| Reduce/Stop Feeding | Hold off after repotting and again whenever light or humidity drops |
| Micronutrients | Usually met by a complete houseplant fertilizer; correct only a diagnosed deficiency |
| Soil pH | Prefers a rich, moisture-retentive, organic potting mix |
Feeding by Growth Stage
Settling in after repotting or propagation
Let newly potted or newly rooted plants establish roots in fresh, rich soil before any feeding.
| Nutrient direction | None – allow roots to establish in fresh potting mix before introducing fertilizer. |
|---|---|
| Timing | Immediately after repotting or once a rooted cutting is first potted up. |
| Frequency | No feeding at this stage; resume once new growth shows the plant has settled in. |
| Fertilizer types | No feeding at this stage; hold off fertilizing until the plant is established in its fresh mix. |
| Precautions | Do not fertilize right after repotting; fresh roots are easily burned by fertilizer salts before they are established. |
Active growth in warmth and humidity
Maintain dense, evenly colored foliage while conditions are warm and humid enough for active growth.
| Nutrient direction | A dilute, balanced feeding supports foliage density without pushing soft, rot-prone growth. |
|---|---|
| Timing | While the plant is actively growing in good warmth and humidity. |
| Frequency | An occasional light feeding is plenty for this modest feeder. |
| Fertilizer types | A dilute, balanced houseplant fertilizer, Rich, organic potting mix renewed at repotting |
| Routine trace nutrients | iron, manganese |
| Precautions | Keep any fertilizer dilute and infrequent; this fine-leaved foliage plant scorches easily from excess fertilizer salts. |
Slowdown in low light or low humidity
Avoid stressing the plant with unused fertilizer when cooler temperatures, low light, or dry air slow growth.
| Nutrient direction | None – withhold fertilizer while growth is slow. |
|---|---|
| Timing | During periods of low light, low humidity, or cooler indoor conditions. |
| Frequency | No feeding at this stage; resume only once active growth returns. |
| Fertilizer types | No feeding at this stage; hold off fertilizing until growth is clearly active again. |
| Precautions | Do not fertilize a slow-growing plant; unused nutrients build up as salts and can scorch the fine foliage. |
Nutrient Deficiency Signs & Corrections
Overall pale, thin foliage and a loss of density in the mat.
| Possible causes | low available nitrogen in old potting mix, infrequent feeding relative to active growth, nutrients leached out by regular misting or watering |
|---|---|
| Appears first on | older growth throughout the mat |
| What to check | time since last feeding or repotting, potting mix condition, watering and misting routine |
| Possible correction | Apply a dilute, nitrogen-containing houseplant fertilizer during active growth and refresh the potting mix if it is old. |
Leaf tips or edges browning and crisping despite consistently moist soil.
| Possible causes | fertilizer salt buildup from feeding that is too frequent or too strong, low humidity concentrating salts at leaf edges, infrequent leaching of the potting mix |
|---|---|
| Appears first on | leaf tips and margins |
| What to check | recent fertilizer strength and frequency, ambient humidity, how often the pot is flushed with water |
| Possible correction | Ease off feeding, flush the potting mix thoroughly with water, and resume with a more dilute feeding. |
New growth turns pale or yellow-green while older foliage stays a normal green.
| Possible causes | potting mix pH outside the plant’s preferred range, waterlogged mix limiting root uptake, naturally low iron availability in the mix |
|---|---|
| Appears first on | newest growth |
| What to check | potting mix drainage and moisture level, time since the mix was last refreshed, recent fertilizer history |
| Possible correction | Improve drainage, refresh the potting mix, and apply a chelated iron product per its label if the pattern persists. |
Pruning, Training & Seasonal Maintenance
Spikemoss has no woody structure and never flowers, so its trimming needs are minimal and continuous: pinch or snip back trailing stems to keep it within its space, and remove dead or browned fronds as they appear. Because it grows year-round in warm, humid conditions, light trimming can be done any time rather than following a fixed season, and it is noted to spread aggressively in favorable spots, so containment trims matter as much as tidying.
Quick Pruning & Maintenance Specs
| Pruning Tolerance | High for light trimming; not a plant with structural wood to cut back hard |
| Primary Pruning Window | All year, as needed (fastest growth in the warm season) |
| Typical Frequency | Light, ongoing trims rather than a scheduled seasonal cut |
| Main Objective | Contain spread; remove dead/browned foliage; keep shape |
| Young Plant Priority | Pinch trailing tips to encourage a dense, low mat |
| Mature Plant Priority | Regular edge trims to stop it spreading beyond its bed/pot |
| Best Tool Type | Precision snips or fingers (soft, delicate stems) |
| Avoid Heavy Pruning During | Cooler/drier spells when regrowth is slow (below about 15C/59F) |
Pruning by Plant Age & Size
Newly Established
Let a newly rooted planting fill in undisturbed; only remove any damaged leaf/stem sections from propagation.
Young / Formative
Pinch the trailing stem tips periodically to encourage denser, low branching rather than a few long runners.
Mature / Established
Trim back any stems creeping beyond the intended area, and snip out patches that have browned or dried out, particularly if humidity has dropped.
Seasonal Pruning Schedule
| Ongoing Sanitary | Snip out dead, browned or dried-out fronds whenever noticed – this is the main recurring task since the plant has no dormant season indoors or in mild climates. |
Special Growth to Remove
Because it is noted as invasive/aggressive under favorable conditions, regularly trim back runners that root beyond the planting area or pot rim; there is no dead old-wood or leaf drop cycle to manage since it stays green and low year-round when happy.
Container & Small-Space Pruning
As a houseplant it needs the same light, ongoing trimming to keep it within its pot; maintain the higher humidity it needs (misting or a pebble tray) since dry indoor air causes browning that then needs trimming out, rather than a pruning-driven fix.
Tools
- Precision snips – the only tool needed for its soft, thin stems and fronds
Tool Hygiene & Disease Risk
Routine care only – clean, sharp snips are enough. Its notable pests (mealybugs, whitefly, spider mites) are not spread by pruning cuts; inspect trimmed material before composting if pests are present.
Cut Placement & Technique
Snip stems just above a healthy node so the remaining stem can branch again; pinch soft tips by hand rather than shearing to avoid crushing the delicate foliage.
Heavy Pruning & Rejuvenation
Does not need or particularly benefit from a hard rejuvenation cut; if a patch becomes leggy or sparse it is generally easier to propagate fresh pieces (it roots readily from stem sections) than to hard-prune old growth back.
Post-Pruning Care
Keep the soil consistently moist and humidity high after trimming, since this is a moisture-loving plant whose main stress after any disturbance is drying out rather than sun exposure.
Common Pruning Mistakes
- Letting it go untrimmed until it spreads well beyond its intended area, given its invasive tendency
- Shearing hard instead of pinching, which tears the soft, delicate stems
- Trimming and then letting humidity drop, causing new cut edges to brown
When NOT to Prune
Avoid heavy trimming during a cool or dry spell when regrowth slows, since cut-back areas will take longer to fill back in.
Recommended Tools (by task)
- precision_snips – all routine trimming, containment cuts and dead-frond removal on this soft-stemmed groundcover/houseplant
Propagation Guide
Selaginella kraussiana is propagated vegetatively, from stem sections that root at the leaf nodes – the site notes this is effectively required since starting new plants from spore is difficult. This is an easy plant to propagate at home once the moisture and rich, well-drained soil it needs are provided.
Quick Propagation Specs
| Best Propagation Method | Stem/node cuttings (rooting at the leaf base) |
| Alternative Methods | Spores (difficult, not practical for home growers) |
| Propagation Difficulty | Easy (vegetative); Specialist (spores) |
| Vegetative True-to-Type | Yes |
| Best Propagation Season | Warmer months; can be done indoors with warmth and humidity year-round |
| Cutting Rooting Time | Typically a few weeks under consistently moist, warm conditions |
| Germination Temperature | Best above 15°C (59°F), can tolerate down to about 7°C (45°F) |
Stem Cuttings
Cutting Type
New roots form at the base of the leaves along the creeping stems, so a stem section with a leaf/root node is used rather than a single leaf.
Cutting Preparation
Two methods work, per the site’s own guidance: (1) cut a stem piece that already has a root forming at the leaf base and place it in water, changing the water every few days until it is well rooted; (2) cut a stem piece and place it directly into soil.
Rooting Setup
For the soil method, use a rich soil – peat-based mix is preferred – and keep it consistently moist without letting it dry out, while still ensuring good drainage. The most reliable approach is to pin or press a stem section into the soil while it is still attached to the mother plant, let it root in place, and only sever the connection once the new piece is established; this roots faster and more reliably than cutting first.
Rooting Hormone
Not necessary – this plant roots readily from stem sections without it.
Rooting Time
The site does not give an exact duration; expect roots to develop over a few weeks under consistently moist, warm, humid conditions.
Spores
Selaginella kraussiana does produce spores, but the site notes starting new plants this way is hard, which is why vegetative propagation from stem sections is the practical and recommended method for home growers.
Pests, Diseases & Troubleshooting
Overview: Spikemosses are moisture- and humidity-loving fern allies with delicate, scale-like foliage that is largely trouble-free when its cultural needs are met; most problems trace back to dry air, stagnant soil moisture, or the sap-sucking insects that colonise soft indoor foliage. Manage it culturally first — steady humidity, gentle airflow, and clean plants — and reach for treatments only when pests are confirmed.
Quick Troubleshooting Overview
| Issue / Pest | Main Symptom | Primary Solution |
|---|---|---|
| Mealybugs | White cottony tufts in leaf junctions; sticky honeydew | Dab with alcohol; insecticidal soap or neem |
| Spider mites | Fine stippling, faint webbing, bronzed dry foliage | Raise humidity; rinse; insecticidal soap or oil |
| Whitefly | Tiny white flies rising when disturbed; sooty mould | Yellow sticky traps; insecticidal soap |
| Fungus gnats | Small black flies at the soil; larvae in wet mix | Let surface dry; sticky traps; Bti drench |
| Leaf browning / crisping | Fronds dry, brown at the edges or tips | Raise humidity, keep evenly moist, shade from sun |
| Root & crown rot | Blackened stems, collapse, sour wet soil | Improve drainage; ease off water; remove rotted parts |
Common Pests & Management
- Mealybugs (Pseudococcus spp.):
- Symptoms: White, cottony, waxy clusters tucked into the crown and where the tiny leaves meet the stems; they excrete sticky honeydew that can turn black with sooty mould. Slow-moving and easily missed on congested, mat-forming foliage.
- Prevention & Control: Isolate the plant and wipe or spot-treat colonies with a cotton bud dipped in diluted rubbing alcohol. Follow with insecticidal soap or a light neem-oil solution, repeating every 7–10 days to catch newly hatched crawlers. Keep new plants quarantined and inspect the crown regularly, as dense growth hides infestations.
- Spider mites (Tetranychus urticae):
- Symptoms: Fine pale stippling on the fronds, a dull bronzed cast, and in bad cases gossamer webbing over the tips — almost always a symptom of air that is too dry. Confirm by tapping foliage over white paper and watching for moving specks.
- Prevention & Control: Prevention is humidity: mist, group plants, or use a pebble tray so the air never dries out. Rinse foliage to dislodge mites, then treat with insecticidal soap or a fine horticultural oil, covering the undersides and repeating twice at weekly intervals. Predatory mites work well in enclosed terrariums.
- Whitefly (Trialeurodes vaporariorum):
- Symptoms: Clouds of tiny white flies lift off when the plant is disturbed; nymphs on the leaf undersides suck sap and produce honeydew and sooty mould, leaving foliage weak and dull.
- Prevention & Control: Hang yellow sticky traps to monitor and thin the adults. Spray insecticidal soap or neem to the undersides in the evening, repeating every few days to break the cycle. Encourage airflow and avoid over-feeding, which produces the soft growth whitefly prefer.
- Fungus gnats (Bradysia spp.):
- Symptoms: Small dark flies running over the soil surface and around the pot; their larvae live in the top layer of permanently wet mix and can nibble tender roots of young plants.
- Prevention & Control: Let the surface dry slightly between waterings even though the plant likes moisture, cover the mix with a thin grit layer, and set yellow sticky traps. For persistent problems drench with Bacillus thuringiensis israelensis (Bti) or use beneficial nematodes.
Diseases & Fungal Issues
- Root & crown/stem rot (Pythium / Phytophthora / Rhizoctonia spp.):
- Symptoms: Stems blacken and collapse at the base, foliage yellows and goes limp, and the mix smells sour — the classic result of soil kept saturated in poor light or cold, stagnant conditions.
- Treatment & Management: Prevention is everything: use a free-draining, organic-rich mix, keep it evenly moist but never waterlogged, and ensure gentle air movement. Remove rotted sections back to healthy tissue, repot into fresh mix, and reduce watering while it recovers. Avoid cold water and cold, still rooms.
- Grey mould (Botrytis cinerea):
- Symptoms: Fuzzy grey-brown mould on soft, congested foliage and dead frond tips, usually in cool, damp, still air with poor drying between waterings.
- Treatment & Management: Increase airflow and reduce leaf wetness in cool spells, remove affected and dead material promptly, and thin overcrowded growth. Sanitation and drier air usually suffice; a copper-based or biological fungicide can be used if it spreads.
Growing Difficulties & Abiotic Problems
- Leaf browning & crisping (low humidity):
- Cause & Symptoms: Fronds dry out, brown at the margins and tips, and the mat looks scorched — caused by dry indoor air, draughts, or letting the mix dry out. This is the single most common complaint with spikemoss.
- Correction Strategy: Keep humidity high and consistent with a pebble tray, grouping, a humidifier, or a terrarium/enclosed case. Maintain even soil moisture, keep it out of hot draughts and heating vents, and mist with soft water in dry spells.
- Sun scorch & bleaching:
- Cause & Symptoms: Direct sun bleaches the colour and burns patches brown; spikemosses are woodland-floor plants adapted to shade and dappled light.
- Correction Strategy: Grow in bright indirect light or light shade, well back from hot windows. Introduce any new light levels gradually and shade from midday sun outdoors.
- Overwatering vs. drying out:
- Cause & Symptoms: Both extremes cause browning: soggy stagnant soil rots the base, while any drying-out of this shallow-rooted plant crisps the foliage almost irreversibly.
- Correction Strategy: Aim for constantly moist but well-aerated mix; water when the surface just begins to feel less wet, and never let the root ball dry completely. Good drainage plus steady humidity is the balance point.
What Helps – Products & Tools
For pest work on spikemoss, the gentle organic staples do the job: insecticidal soap and light horticultural or neem oil for mealybugs, mites and whitefly, rubbing alcohol on a cotton bud for spot-treating mealybugs, yellow sticky traps for whitefly and fungus gnats, and a Bti drench for gnat larvae. On the disease side a copper-based fungicide handles grey mould if sanitation alone falls short. The best ‘tools’, though, are a humidifier or pebble tray and a free-draining, organic-rich mix — keep the air moist and the roots aerated and this plant rarely needs sprays.
