How to Grow Fern Allies
Fern Allies
Lycopodiophyta and Selaginellophyta (divisions)
grassFern allies are ancient non-flowering plants including clubmosses (Lycopodium) and spikemosses (Selaginella) that thrive in humid, tropical environments. They are primitive vascular plants that reproduce via spores rather than seeds, adding delicate, fine-textured foliage to tropical arrangements. These plants are prized for their cascading forms and feathery appearance in high-humidity settings.
When should you plant Fern Allies in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Fern Allies timeline · Pittsburgh, PA (Zone 6b)
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Plant Fern Allies
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Fern Allies
Late summer into fallBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Fern Allies dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Zones 10-12 outdoors; zones 9+ as houseplants in controlled tropical environments
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Spore Germination
4-12 weeksMicroscopic spores develop into small prothalli (gametophytes) in very humid conditions
Maintain 85-95% humidity with warm temperatures (70-80°F); spores germinate slowly over weeks to months
Young Sporophyte
2-4 weeksFirst tiny fronds emerge from the prothallus; plant develops its first true roots
Maintain constant high humidity; use fine misting; avoid drying out the medium; provide bright indirect light
Vegetative Growth
Variable, 2-6 months to maturityPlant establishes rhizomes and develops characteristic fine, feathery fronds; colony expands
Maintain 60-80% humidity; ensure consistent moisture; apply diluted liquid fertilizer monthly; pinch back leggy growth to encourage bushiness
Mature
OngoingPlant reaches full size with dense, cascading or creeping foliage; may show sporangia (spore structures) on frond undersides
Continue consistent watering and humidity; remove dead fronds; repot annually if in containers
Spore Production
Seasonal, varies by speciesMature plants produce spores in specialized structures on frond undersides or cone-like strobili
No special care needed; spore release occurs naturally in humid conditions; collect spores if propagating
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Isolate plant; spray with insecticidal soap or neem oil; remove with cotton swab dipped in alcohol
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Remove by hand; apply horticultural oil or insecticidal soap; repeat treatments every 7-10 days
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Allow soil surface to dry briefly between waterings; use yellow sticky traps; apply sand layer on soil surface
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Increase humidity; mist frequently; spray with neem oil or insecticidal soap if severe
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Improve drainage; reduce watering frequency; repot in fresh, sterile soil; remove affected roots
Uses
Tropical Terrarium & Arrangement Decor
HouseholdFern allies are classic terrarium plants providing delicate, cascading texture in high-humidity glass containers and tropical displays. Their fine fronds create lush, verdant backgrounds for other tropical plants. [source]
Air Purification & Indoor Humidity
HouseholdThese plants improve indoor air quality through transpiration and help increase ambient humidity when misted regularly, benefiting other tropical houseplants. They contribute to creating natural, humid microclimates indoors. [source]
Habitat for Tropical Insects & Microorganisms
WildlifeFern allies provide shelter and microhabitats for beneficial insects, mites, and microorganisms in tropical gardens, supporting biodiversity. They are especially valuable in paludarium (semi-aquatic) setups with amphibians. [source]
Floral & Botanical Design
CraftDelicate fern ally fronds are used by florists and botanical designers in fresh and preserved tropical arrangements, creating fine-textured accents. They add movement and softness to corsages and high-end floral compositions. [source]
Traditional & Ethnobotanical Uses
MedicinalVarious fern ally species have been used in traditional Chinese, Ayurvedic, and Amazonian medicine for treating respiratory conditions and inflammation. Selaginella species in particular have documented ethnobotanical applications. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Fern allies are not harvested for consumption but are propagated by spores (collected from mature fronds) or vegetative division of rhizomes. Collect spores by wrapping mature fronds in paper and allowing spores to drop naturally, or divide crowns in spring. Individual fronds can be trimmed for fresh tropical arrangements.
Fun Facts
- 🌱 Fern allies are among the oldest land plants on Earth, with fossils dating back over 400 million years to the Devonian period—they were dominant during the Carboniferous era when they grew as massive tree-sized plants.
- 🌱 Unlike ferns, which have large fronds, many fern allies like clubmosses produce tiny, scale-like leaves arranged in spiral or opposite patterns, giving them a distinctive feathery or moss-like appearance.
- 🌱 Some Selaginella species are 'resurrection plants' that can survive complete desiccation and revive when rehydrated, making them remarkably resilient despite their need for high humidity in cultivation.
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