Repotting guide

When & how to repot Euphorbia caput-medusae (Euphorbia caput-medusae)

Also called medusa's head euphorbia, snake euphorbia.

More about euphorbia caput-medusae

About Euphorbia caput-medusae

Euphorbia caput-medusae · also called medusa's head euphorbia, snake euphorbia · houseplant

Euphorbia caput-medusae, the medusa's head, is a Cape Province succulent with a thick central stem ringed by many long, snaking, tubercled branches that writhe outward like serpents. Tiny greenish cyathia appear at the branch tips. Indoors it demands full sun, gritty fast-draining soil, and a dry winter rest to keep the iconic medusa form tight.

Mature size: Central head 8-15 cm across with arms 20-30 cm long, forming a sprawling clump 30-50 cm wide over time.

How to tell euphorbia caput-medusae needs repotting

Repotting on a calendar is less reliable than reading the plant. For euphorbia caput-medusae, 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 euphorbia caput-medusae

Every 2–3 years, into bone-dry mix. Euphorbia caput-medusae's growth habit — medusoid succulent: a short thick central trunk crowned by numerous long, radiating, finger-like tubercled branches that sprawl outward. — sets the pace. Euphorbia caput-medusae, the medusa's head, is a Cape Province succulent with a thick central stem ringed by many long, snaking, tubercled branches that writhe outward like serpents. Tiny greenish cyathia appear at the branch tips. Indoors it demands full sun, gritty fast-draining soil, and a dry winter rest to keep the iconic medusa form tight.

What size pot to step euphorbia caput-medusae up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Euphorbia caput-medusae 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 euphorbia caput-medusae

Spring or summer, while euphorbia caput-medusae 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 euphorbia caput-medusae

Repot dry. Do not water euphorbia caput-medusae 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 gritty cactus/succulent 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 euphorbia caput-medusae 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 euphorbia caput-medusae 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 euphorbia caput-medusae

Euphorbia caput-medusae wants gritty cactus/succulent mix. Cactus compost amended with plenty of pumice, perlite, or grit for rapid drainage, ideally around half mineral. Terracotta and a generous drainage hole help the central caudex dry quickly. Avoid heavy peat-based mixes. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting euphorbia caput-medusae — frequently asked questions

How often should you repot euphorbia caput-medusae?

Every 2–3 years, into bone-dry mix for euphorbia caput-medusae. Repot euphorbia caput-medusae every 2–3 years into a snug pot of gritty cactus/succulent 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 euphorbia caput-medusae need?

When is the best time of year to repot euphorbia caput-medusae?

Should you water euphorbia caput-medusae after repotting?

No — not straight away. Repot euphorbia caput-medusae 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 euphorbia caput-medusae after repotting?

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