Fertilising guide
How to fertilise Cushion Moss Selaginella (Selaginella martensii)— schedule & NPK
Also called Martens Spikemoss, Trailing Selaginella, Variegated Selaginella.
More about cushion moss selaginella
About Cushion Moss Selaginella
Selaginella martensii · also called Martens Spikemoss, Trailing Selaginella · houseplant
Selaginella martensii is a popular terrarium and houseplant spikemoss from Mexico and Central America, known for its arching, branching stems and bright green foliage — variegated cultivars also exist. It performs best in high humidity. No known toxicity; not listed by ASPCA as harmful.
Growth habit: Spreading, semi-upright branching perennial with aerial roots
What fertiliser cushion moss selaginella actually wants — and why
Cushion Moss Selaginella is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for cushion moss selaginella: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed cushion moss selaginella, and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For cushion moss selaginella:
Apply a balanced liquid fertiliser at quarter strength once a month during spring and summer. Feed sparingly — Selaginella has modest nutritional needs and excess fertiliser causes burnt tips. Treat that as once a month between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
The dormant-season rule matters more than the exact interval: skip feeding entirely when cushion moss selaginella is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for cushion moss selaginella
Half strength is the safe default for cushion moss selaginella — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
Feeding always goes onto already-damp soil, never dry roots — water cushion moss selaginella first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the cushion moss selaginella watering schedule.
Signs you are over-feeding cushion moss selaginella
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for cushion moss selaginella:
- Brown, crispy leaf tips and edges with no sign of underwatering.
- A white, crusty salt deposit on the soil surface or pot rim.
- Weak, pale, stretched new growth that flops.
- Lower leaves yellow and drop while the soil is correctly watered.
Signs you are under-feeding cushion moss selaginella
- Uniformly pale or yellow-green leaves, oldest first.
- Noticeably small new leaves and stalled growth in good light and season.
- A generally tired, lacklustre look despite correct watering and light.
If the symptoms point at watering, light or roots rather than nutrition, the full cushion moss selaginella care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of cushion moss selaginella with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Organic vs synthetic feeds for cushion moss selaginella
Organic options
A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.
Synthetic / liquid feeds
A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising cushion moss selaginella — frequently asked questions
What fertiliser does cushion moss selaginella need?
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Cushion Moss Selaginella is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
How often should I feed cushion moss selaginella?
Apply a balanced liquid fertiliser at quarter strength once a month during spring and summer. Feed sparingly — Selaginella has modest nutritional needs and excess fertiliser causes burnt tips. Apply a balanced liquid fertiliser at quarter strength once a month during spring and summer. Feed sparingly — Selaginella has modest nutritional needs and excess fertiliser causes burnt tips. Treat that as once a month between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
What strength of feed for cushion moss selaginella?
Half strength is the safe default for cushion moss selaginella — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding cushion moss selaginella look like?
Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding cushion moss selaginella year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.
Should I flush the soil of cushion moss selaginella?
Flush the pot of cushion moss selaginella with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Keep reading
- Cushion Moss Selaginella care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water cushion moss selaginella — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise rhaphidophora beccarii
- How to fertilise rhaphidophora hongkongensis
- How to fertilise epipremnum aureum global green
- All 11687 fertilising guides in the Growli library