Repotting guide

When & how to repot Crassula Alstonii (Crassula alstonii)

Also called Alston's crassula, tiny towers crassula.

More about crassula alstonii

About Crassula Alstonii

Crassula alstonii · also called Alston's crassula, tiny towers crassula · houseplant

Crassula alstonii is a prized dwarf South African succulent that forms a near-spherical column of tiny grey-green leaves stacked so tightly the plant looks like a fuzzy ball or miniature tower. Slow-growing and collector-favoured, it demands very sharp drainage, lean watering and strong light, and like all Crassula it is toxic to pets.

Mature size: Typically just 3-6 cm tall and wide; an exceptionally slow grower that stays in miniature for years.

Watch for — Loss of compact form: Insufficient light makes the tightly stacked leaves loosen and elongate, spoiling the ball shape. Move it to the brightest spot, with direct sun, to keep the column dense.

How to tell crassula alstonii needs repotting

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

Roots growing out of the drainage holes, or the rootball lifting the plant proud of the rim.
Soil that has shrunk away from the pot sides and no longer holds water.
The pot is unstable because the plant has grown top-heavy.
Old, compacted, broken-down mix that stays wet too long — for a succulent that is a rot risk, so refresh it even if the pot size is fine.

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 crassula alstonii

Every 2–3 years, into bone-dry mix. Crassula Alstonii's growth habit — a slow-growing, geophytic dwarf succulent that forms a single dense, near-spherical column or low mound of minute, tightly overlapping grey-green leaves with a soft, velvety surface. mature plants may offset to form small clusters and, in season, push short flower stalks bearing tiny pale flowers above the rosette. — sets the pace. Crassula alstonii is a prized dwarf South African succulent that forms a near-spherical column of tiny grey-green leaves stacked so tightly the plant looks like a fuzzy ball or miniature tower. Slow-growing and collector-favoured, it demands very sharp drainage, lean watering and strong light, and like all Crassula it is toxic to pets.

What size pot to step crassula alstonii up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Crassula Alstonii stores water and rots in a large pot of slow-drying soil. A tight terracotta pot that dries fast is far safer than a generous plastic one. Never up-pot a succulent by several sizes.

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 crassula alstonii

Spring or summer, while crassula alstonii is in active growth and warm, is best — roots recover fastest then, and the plant is not sitting in cool damp soil. Avoid repotting a succulent in winter dormancy.

Step-by-step: repotting crassula alstonii

Repot dry. Do not water crassula alstonii for several days first. Working with dry roots and dry mix dramatically lowers the rot risk for a succulent.
Pick a snug, fast-draining pot. Choose terracotta one size up at most, with a drainage hole. Have gritty extremely free-draining mineral mix ready.
Tip it out and clean the roots. Slide the plant out, crumble off the old soil, and trim any black, mushy or dead roots with clean snips.
Pot into dry mix. Set crassula alstonii at its original depth in dry gritty mix, firming gently. Do not bury the stem deeper than it was.
Wait a week before watering. Leave it completely dry and out of harsh sun for about 7 days so any damaged roots callus. Only then water lightly.

Aftercare

Keep crassula alstonii completely dry and out of fierce sun for about a week so any nicked roots callus before they meet moisture; watering a freshly repotted succulent is the classic way to rot it. Then resume the normal lean, dry rhythm. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for crassula alstonii

Crassula Alstonii wants extremely free-draining mineral mix. Use a very gritty, low-organic medium: cactus and succulent compost cut heavily with pumice, grit or coarse sand to at least half mineral content. A grit top-dressing keeps the dense rosette off wet soil. Standard potting mix holds far too much moisture for this rot-prone species. A small clay pot with drainage holes helps the soil dry quickly. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting crassula alstonii — frequently asked questions

How often should you repot crassula alstonii?

Every 2–3 years, into bone-dry mix for crassula alstonii. Repot crassula alstonii every 2–3 years into a snug pot of extremely free-draining mineral mix, ideally in spring or summer. Let it sit in dry soil and do not water for about a week afterwards so any nicked roots can callus. Over-potting and watering straight away is what rots succulents.

What size pot does crassula alstonii need?

When is the best time of year to repot crassula alstonii?

Should you water crassula alstonii after repotting?

No — not straight away. Repot crassula alstonii into dry mix and wait about a week before the first watering so any damaged roots callus over. Watering a freshly repotted succulent is the single most common way to rot one.

Should you fertilise crassula alstonii after repotting?

Not immediately. Wait about 3 weeks after repotting crassula alstonii. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.