Selaginella (Spikemoss) for Terrariums

Common names: Spikemoss, Clubmoss (not a true moss)
Genus: Selaginella
Family: Selaginellaceae
Plant type: Primitive vascular plant (lycophyte)

Overview

Selaginella is one of the best plants for terrariums, valued for its fern-like, mossy texture, vivid green tones, and love for constant humidity. Despite the name “spikemoss,” it is not a moss or fern, but an ancient plant lineage dating back over 300 million years.

Many species are rainforest floor plants that thrive in low light, saturated humidity, and evenly moist substrates—conditions that match terrariums perfectly.

Why Selaginella Excels in Terrariums

• Thrives at 80–100% humidity

• Stays lush in low light

• Creates a dense, carpeted look

• Recovers well from pruning

• Excellent contrast with Fittonia, ferns, and mosses

Best Selaginella Species for Terrariums

🌿 Selaginella kraussiana

• Bright green, creeping habit

• Fast spreader

• Ideal groundcover

🌿 Selaginella willdenowii

• Iridescent blue-green leaves

• Upright, dramatic form

• Needs slightly more light

🌿 Selaginella uncinata

• Metallic turquoise sheen

• Stunning in shaded terrariums

• Slow-growing but striking

🌿 Selaginella martensii

• Upright, fern-like growth

• Popular cultivar: ‘Jori’

⚠️ Avoid desert species (e.g., Selaginella lepidophylla) in terrariums—they prefer dry conditions.

Appearance

• Foliage: Tiny scale-like leaves in dense rows

• Color: Bright green to blue-green or iridescent

• Growth habit: Creeping, trailing, or upright (species-dependent)

• Height: 5–20 cm

• Spread: Unlimited under ideal conditions

Light Requirements

• Best: Low to medium indirect light

• Avoid: Direct sunlight (burns foliage quickly)

• Too much light causes yellowing or crisping

Watering & Moisture

Selaginella must never dry out.

• Soil should stay constantly moist

• Use soft or filtered water if possible

• In closed terrariums, mist lightly as needed

Drying even once can cause:

• Browning

• Stem dieback

• Permanent damage (species-dependent)

Humidity

• Ideal: 80–100%

• Struggles in open-air pots

• Perfect for:

  • Closed terrariums

  • Vivariums

  • Orchid cases

Low humidity causes immediate decline.

Temperature

• Optimal: 18–26°C (65–80°F)

• Minimum: 15°C (59°F)

• Avoid drafts and temperature swings

Substrate (Terrarium Soil)

Best mix:

• Coco coir or peat moss

• Fine bark

• Perlite or sand

• Leaf litter on top

The substrate should be moist, airy, and slightly acidic.

Fertilization

• Minimal feeding

• Use very diluted fertilizer (¼ strength) every 2–3 months

• Overfeeding causes weak, floppy growth

Pruning & Maintenance

• Trim runners to control spread

• Remove brown or dying tips promptly

• Can be shaped into carpets or mounds

Cuttings can be replanted directly.

Propagation

Vegetative propagation only (for hobbyists):

• Cut healthy stems with nodes

• Press into moist substrate

• Maintain high humidity

• Roots form in 1–3 weeks

Spore reproduction occurs naturally but is rarely used in home setups.

Common Problems

Terrarium Companions

Excellent with:

• Fittonia

• Miniature ferns

• Mosses

• Peperomia (humid types)

• Begonia (mini species)

Avoid pairing with drought-tolerant plants.

Aquatic Use – Important Note

🚫 Not an aquarium plant

• Cannot live submerged

• Will rot underwater

• Suitable only for emersed, high-humidity environments

Summary

Selaginella is:

• One of the best terrarium groundcovers

• Humidity-loving and moisture-dependent

• Low-light tolerant

• Ideal for closed or semi-closed systems