Repotting guide

When & how to repot Spreading Selaginella (Selaginella pallescens)

Also called Sweat Plant, Basket Selaginella, Lace Fern.

More about spreading selaginella

About Spreading Selaginella

Selaginella pallescens · also called Sweat Plant, Basket Selaginella · houseplant

Selaginella pallescens, often called Sweat Plant or Basket Selaginella, is a compact spikemoss from Central America prized for its lush, finely textured pale-green foliage. It excels in terrariums and humid displays. No ASPCA toxicity listing; the genus is widely regarded as pet-safe.

Mature size: 10-20 cm tall, spreading to 30 cm wide

Watch for — Overwatering and crown rot: Waterlogged soil leads to root and crown rot. Ensure good drainage and avoid wetting the growing crown directly.

How to tell spreading selaginella needs repotting

Repotting on a calendar is less reliable than reading the plant. For spreading selaginella, watch for these signs:

Roots poking out of the drainage holes or coiling visibly around the inside of the pot.
You are watering far more often than you used to because the rootball dries out within a day or two.
Water runs straight through and out the bottom without soaking in.
Top growth has slowed or new spreading selaginella leaves are noticeably smaller than older ones despite good light.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot spreading selaginella

Every 12–18 months — sooner if roots show fast. Spreading Selaginella's growth habit — compact, low-spreading mat-forming perennial — sets the pace. Selaginella pallescens, often called Sweat Plant or Basket Selaginella, is a compact spikemoss from Central America prized for its lush, finely textured pale-green foliage. It excels in terrariums and humid displays. No ASPCA toxicity listing; the genus is widely regarded as pet-safe.

What size pot to step spreading selaginella up to

Step up one pot size — about 2–3 cm (an inch) wider. Spreading Selaginella grows fast, so it will fill that space within a season, but jumping several sizes at once still backfires: the unused soil stays soggy and rots even a vigorous root system. One size at a time, every year or so, is the rhythm.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot spreading selaginella

Early spring, just as new growth restarts, is the ideal window for spreading selaginella. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting spreading selaginella

Time it for spring. Repot spreading selaginella in early spring as growth restarts so it re-roots quickly into the fresh soil.
Choose one size up. Pick a pot about 2–3 cm wider with drainage holes. One step only — a much bigger pot stays soggy and rots roots.
Ease the plant out. Water lightly the day before, then tip spreading selaginella out and gently loosen any roots circling the bottom of the rootball.
Repot at the same depth. Put a layer of fresh fine, moisture-retentive, peat-free organic mix in the new pot, set the plant so its soil line is unchanged, and backfill, firming lightly.
Water and pause feeding. Water once to settle the soil. Hold off fertiliser for about a month — fresh mix already has nutrients and feeding now burns new roots.

Aftercare

Water spreading selaginella once to settle the soil, then let the surface dry before watering again — fresh mix around the roots stays wetter than the old compacted ball, so the commonest post-repot mistake is overwatering. Keep it out of direct sun for a week or two while roots re-establish. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for spreading selaginella

Spreading Selaginella wants fine, moisture-retentive, peat-free organic mix. A mix of fine coconut coir, composted bark, and a small amount of perlite works well. Slightly acidic pH around 5.5–6.5 is preferred. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting spreading selaginella — frequently asked questions

How often should you repot spreading selaginella?

Every 12–18 months — sooner if roots show fast for spreading selaginella. Repot spreading selaginella roughly every 12–18 months, in early spring as growth restarts. It grows fast and circles its pot quickly, so step up one size (about 2–3 cm wider) into fresh fine, moisture-retentive, peat-free organic mix. Don't jump several sizes — that soggy excess soil is what rots vigorous roots.

What size pot does spreading selaginella need?

When is the best time of year to repot spreading selaginella?

Can you put spreading selaginella straight into a much bigger pot?

No. Even a fast-growing spreading selaginella should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise spreading selaginella after repotting?

Not immediately. Wait about 4 weeks after repotting spreading selaginella. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.