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: Green, pinnately arranged (feather-like) leaves on spreading fronds. 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 patula (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 patula is a tropical-to-subtropical spikemoss valued for its pinnate foliage; it needs warm, humid, shaded conditions and has minimal tolerance for cold or dry air. Grow it outdoors as a shade groundcover only in frost-free climates, or as a humidity-loving houseplant elsewhere.
Quick Climate Specifications
| Climate Zones | Tropical, subtropical; in Mediterranean climates needs extra summer moisture and shelter, or grow indoors |
|---|---|
| USDA Hardiness Zones | Reliable outdoors in zone 11+; possible in 10b with attentive winter protection |
| Optimal Temp Range | Above approximately 15°C (59°F) |
| Cold Damage Begins | Below approximately 7°C (45°F) |
| Frost Tolerance | None |
| Light Conditions | Full shade |
Sunlight & Light Exposure
Optimal Light Setup
A true shade plant – provide full, even shade outdoors or bright, indirect light indoors; it does not want direct sun.
Shade & Heat Management
Keep it in deep shade; direct sun combined with summer heat quickly scorches the delicate pinnate foliage.
Best Exposure / Orientation
A shaded bed or north-facing spot outdoors, or a position away from bright windows indoors, works well.
Temperature Extremes & Hardiness
USDA Hardiness & Regional Limits
Grown outdoors year-round mainly in zone 11+; in zone 10b it can survive with a sheltered microclimate and winter protection, though it is not fully hardy there.
Cold Damage & Winter Protection
Growth is damaged once temperatures fall much below about 7°C (45°F); bring potted specimens under cover before cold nights set in.
Frost Sensitivity
Frost-tender with no meaningful frost tolerance.
Extreme Heat Tolerance
Tolerates humid tropical heat well, but hot, dry conditions – including a dry Mediterranean summer – call for extra shade and atmospheric moisture.
Wind, Humidity & Microclimate
Humidity Preferences
High humidity is one of its core requirements for healthy growth.
Dry-Air Tolerance
Poor – dry air, whether from indoor heating or an arid summer, stresses the foliage; misting or a humidity tray helps indoors.
Rainfall & Seasonal Moisture
In Mediterranean-type climates with dry summers, supplemental moisture and shade are needed to offset naturally low rainfall during the growing season.
Microclimate Recommendations
A humid, shaded spot – near water features or in a shaded greenhouse outdoors, or a humid room such as a bathroom indoors – away from dry heating vents suits it best.
Growing in Pots, Balconies & Indoors
Spikemoss is a low, mossy, spreading ground-cover fern-ally (only 5-15 cm / 2-6 in tall) that makes an easy, attractive houseplant – as long as you keep the air humid. It thrives in full shade, so it does not need a sunny window and is happy well inside a room.
Indoors the biggest challenge is not light but dry air: near heaters or air-conditioning the delicate foliage crisps quickly, so it does best in a terrarium, bathroom, or on a pebble tray.
Quick Details
- Container Size: A wide, shallow pot 40-50% larger than the root ball; pot up when roots fill it.
- Indoor Suitability: A good houseplant – keep the air humid.
- Best Spot: Full shade to bright indirect light; away from dry drafts, heaters and AC.
- Soil & Drainage: Rich, organic mix – potting or peat soil with perlite; kept evenly moist but free-draining.
- Watering in Pots: Water regularly and never let it dry out fully; pots dry faster than open ground.
Indoors & On the Windowsill
- Genuine houseplant: Yes – it grows happily indoors. Because it wants full shade, it suits shadier rooms where sun-loving plants would sulk.
- Humidity is key: Keep it away from heating and cooling vents that dry the air; group it with other plants, stand it on a damp pebble tray, or grow it in a terrarium or bathroom.
- Windowsill: A shaded or north-facing sill is fine; avoid hot direct sun, which scorches the fine foliage.
On a Balcony or Patio
- Light & shelter: In mild climates it makes a lush filler for shady, sheltered balconies; keep it out of wind and direct sun, both of which dry it out fast.
- Container reality: Reflected heat from walls and paving dries small pots quickly, so check moisture often and mist in dry spells.
Choosing the Pot, Soil & Long-Term Care
- Pot & drainage: A wide, shallow pot 40-50% bigger than the root ball suits its spreading, shallow roots. Give it strong drainage holes and skip a standing-water saucer to avoid root rot; terracotta breathes and dries faster, while glazed or plastic pots hold moisture longer.
- Potting mix: A light, aerated, organic-rich mix – potting soil, or peat/coir with perlite, enriched with a little humus or compost.
- Feeding: Potted plants use up their food faster because nutrients wash out with every watering, so feed lightly but more regularly than plants growing in open ground.
- Repotting: Every few years, once it has filled its final pot, refresh the soil, trim some roots and leaves, and top up with humus and mulch to hold moisture.
- Feeding note: A small amount of fertilizer every few years is enough, as the grower advises, plus humus and mulch.
Growing this plant in a greenhouse
A greenhouse can give selaginella patula frost protection and cold protection.
Greenhouse at a glance
| Greenhouse suitability | Good - clearly useful |
|---|---|
| Main benefits | frost protection, cold protection |
| Season extension | earlier spring & later autumn |
| Outdoor protection advisable below | about 7°C |
| Maintain greenhouse minimum | around 7°C for active growth |
| Suitable types | unheated greenhouse, polycarbonate greenhouse |
| Heating | Heating is optional - useful mainly for winter growing in cold areas. |
Related greenhouse guides
- Greenhouses: How to Choose the Right Greenhouse
- Polycarbonate Greenhouses: What to Look for Before Buying
Fertilizing & Feeding
A light feeder overall: fertilizer is needed only rarely, since rich, organic, consistently moist soil already supplies most of what this shade-loving foliage plant needs.
Quick Fertilizing Specs
| Feeding Level | Light feeder |
|---|---|
| Main Nutrient Priority | A balanced fertilizer at reduced strength to support fresh green pinnate foliage |
| Best Feeding Period | During active growth in warm, humid conditions |
| Organic Options | Compost, humus, and organic matter worked into rich soil |
| Reduce/Stop Feeding | Hold off feeding in cooler weather or when growth slows |
| Micronutrients | Usually supplied by rich, organic soil; correct only diagnosed deficiencies |
Feeding by Growth Stage
Establishment after planting or repotting
Let new roots settle into rich, moist soil before asking the plant to take up fertilizer.
| Nutrient direction | None – withhold fertilizer while roots establish. |
|---|---|
| Timing | The first weeks after planting, dividing, or repotting. |
| Frequency | No feeding at this stage. |
| Fertilizer types | No feeding at this stage; hold off fertilizing until new roots are established and active growth resumes. |
| Precautions | Do not fertilize a freshly planted or repotted division; wait for active growth before feeding. |
Active growth in warmth and humidity
Support fresh green pinnate foliage while the plant is actively growing in warm, humid conditions.
| Nutrient direction | A balanced, nitrogen-leaning fertilizer at reduced strength supports steady foliage growth. |
|---|---|
| Timing | Through the warm season while temperature and humidity favor active growth. |
| Frequency | Infrequent, light feeding is usually enough for this modest feeder. |
| Fertilizer types | A balanced complete fertilizer diluted to a gentle strength, Compost or organic matter worked into the soil surface |
| Routine trace nutrients | iron, manganese |
| Precautions | Keep feeding light and infrequent; this shade-loving foliage plant is easily overfed and rich organic soil already supplies much of its needs. |
Cool or low-light slowdown
Avoid pushing growth when cooler temperatures or lower light slow the plant down.
| Nutrient direction | None – growth has slowed and feeding is not needed. |
|---|---|
| Timing | Cooler months or periods of reduced light and slower growth. |
| Frequency | No feeding while growth is slow. |
| Fertilizer types | No feeding at this stage; withhold fertilizer until active growth resumes. |
| Precautions | Do not fertilize while growth is slow; unused nutrients can build up as salts in the soil. |
Nutrient Deficiency Signs & Corrections
New fronds emerge smaller and paler than usual, and overall growth slows.
| Possible causes | low available soil nitrogen, nutrient leaching from consistently moist soil, very infrequent feeding over a long period |
|---|---|
| Appears first on | newest fronds |
| What to check | recent feeding history, soil organic matter and moisture, overall growth rate |
| Possible correction | Resume light, balanced feeding during active growth and refresh organic matter in the soil. |
New fronds turn pale to yellowish while the finer veining stays greener.
| Possible causes | alkaline or high soil pH limiting iron uptake, waterlogged or compacted soil reducing root function, general root stress from poor drainage |
|---|---|
| Appears first on | newest fronds |
| What to check | soil pH and drainage, watering consistency, root condition when repotting |
| Possible correction | Correct soil pH toward the plant’s preference and apply a chelated iron product per its label. |
Frond tips brown or dry out despite consistently moist soil.
| Possible causes | fertilizer salt buildup from feeding this light feeder too often, mineral buildup from hard water, inconsistent watering concentrating salts in the soil |
|---|---|
| Appears first on | frond tips |
| What to check | recent fertilizer frequency and strength, water source and mineral content, watering consistency |
| Possible correction | Ease off feeding, flush the soil with plain water, and resume only light, infrequent feeding. |
Pruning, Training & Seasonal Maintenance
Selaginella patula is a spikemoss with feathery, pinnate fronds and a more spreading, trailing habit than compact mat-forming Selaginella species – it never flowers. Pruning is grooming and containment: removing dead fronds and trimming or pinching back trailing growth so it doesn’t sprawl past its space or, in a hanging container, become sparse and stringy at the base. It tolerates trimming year-round, with no bloom cycle to time around.
Quick Pruning & Maintenance Specs
| Pruning Tolerance | Moderate (grooming and shaping, not structural) |
| Primary Pruning Window | Any time of year |
| Typical Frequency | Light, ongoing grooming as fronds brown or trailing growth spreads or thins at the base |
| Main Objective | Remove dead fronds; pinch trailing stems for fullness; contain spread |
| Young Plant Priority | Let the plant fill in; no shaping needed yet |
| Mature Plant Priority | Pinch trailing stems to prevent a bare, leggy base; contain spread |
| Best Tool Type | Precision snips |
Pruning by Plant Age & Size
Newly Established
No trimming needed while the small plant (5–15cm) is filling in; remove only visibly damaged fronds from planting.
Young / Formative
No structural training applies to this creeping/trailing plant, but pinching trailing stem tips early encourages branching from the base rather than a few long, sparse runners – more important for this species than for the more naturally compact Selaginella species.
Mature / Established
Pinch or trim trailing stems periodically to keep growth full from the base outward rather than leggy, and thin dense patches occasionally for airflow, since this species is noted to attract mealybugs, whitefly and spider mites in humid, poorly-ventilated conditions.
Special Growth to Remove
Dead or browned fronds, snipped close to their base. Trailing stems that have spread and rooted beyond where they are wanted (this species is noted as invasive in favorable conditions) can be trimmed or lifted out.
Container & Small-Space Pruning
This species’ trailing habit suits hanging baskets and elevated pots, where pinching back the longest runners keeps the whole plant full rather than concentrated at the tips with a bare center. At repotting – typically every few years, or once roots fill the pot – growers are advised to switch the soil and cut back some of the roots and leaves together.
Tools
Precision snips are the only tool needed for this fine-fronded, soft-stemmed plant.
Tool Hygiene & Disease Risk
Routine risk – clean tools are sufficient. The pests noted (mealybugs, whitefly, spider mites) are not cut-transmissible, so blade disinfection is not a priority; improving airflow through thinning helps more with pest prevention.
Cut Placement & Technique
Snip dead fronds close to their base. Pinch trailing stem tips just above a node to encourage branching and fuller growth along the runner rather than at the tip alone.
Post-Pruning Care
Maintain consistent humidity and soil moisture after trimming, since this species does not tolerate drying out; no feeding is needed immediately after a light trim.
Common Pruning Mistakes
Only trimming the trailing tips and never pinching further back, which leaves a bare, leggy base with foliage only at the ends. Letting trailing growth spread and root untrimmed into neighboring pots or beds.
When NOT to Prune
Avoid heavy trimming right after repotting or root-pruning, while the plant is recovering from root disturbance.
Recommended Tools (by task)
| Task | Plant Age/Size | Stem/Frond Size | Tool Category | Why |
| Remove dead fronds / pinch trailing stems | Any age, 5–15cm | Fine fronds and thin trailing stems | precision_snips | Delicate, controlled cuts suited to soft, small-scale foliage |
Propagation Guide
Selaginella patula is propagated almost entirely by vegetative means: sections of trailing stem rooting from the leaf bases, either rooted in water or directly in moist, rich soil. Starting new plants from spores is possible in principle but is difficult and rarely practical, so vegetative propagation is both the easiest and the standard method, making this an easy plant to propagate at home.
Quick Propagation Specs
| Best Propagation Method | Vegetative propagation (rooted stem/leaf-base cuttings) |
| Alternative Methods | Water-rooted cuttings; spores (difficult, rarely used) |
| Propagation Difficulty | Easy |
| Vegetative True-to-Type | Yes |
| Best Propagation Season | Spring to summer (avoid the hottest summer days in cooler hardiness zones) |
| Cutting Rooting Time | Typically a few weeks under warm, humid conditions |
Stem Cuttings
Cutting Type
A trailing stem section still bearing leaves; roots naturally form at the base of the leaves along the stem.
Best Timing
Spring through summer, avoiding the hottest days of summer where grown outdoors in marginal hardiness zones.
Cutting Preparation
Where possible, root the leaf/stem section while it is still attached to the mother plant — this speeds rooting and improves success — then sever the connection only once the new section has established its own roots.
Rooting Setup
Two options work: (1) place the cut leaf/stem section with its root in water, changing the water every few days; or (2) insert it directly into rich, peat-based soil kept consistently moist (never allowed to dry out) with good drainage, in high humidity.
Rooting Hormone
Not required – nodal rooting occurs readily on its own.
Rooting Time
Typically a few weeks under warm, humid conditions.
Spores
Selaginella patula does produce spores, but starting new plants from spores is difficult, so it is rarely used in practice; vegetative propagation from rooted stem/leaf-base sections is the far more reliable and practical route 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.
