Repotting guide

When & how to repot String of dolphins (Senecio peregrinus)

Also called dolphin plant, flying dolphins.

About String of dolphins

Senecio peregrinus · also called dolphin plant, flying dolphins · houseplant

String of dolphins is a quirky succulent hybrid with leaves shaped like leaping dolphins. A cross between string of pearls and Senecio articulatus. Mildly toxic to pets like its parents and demands bright light to keep its distinctive leaf shape.

Curio x peregrinus (Senecio x peregrinus), not a wild species but an intergeneric hybrid of Curio rowleyanus (string of pearls) and a Curio articulatus relative; the leaves curve into two small points resembling leaping dolphins.

Requires a gritty, fast-draining succulent or cactus mix; the fleshy dolphin leaves store water, so the roots must never sit wet.

Mature size: 30-60 cm trailing

Sources: en.wikipedia.org, plants.ces.ncsu.edu

How to tell string of dolphins needs repotting

Repotting on a calendar is less reliable than reading the plant. For string of dolphins, 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 string of dolphins

Every 2–3 years, into bone-dry mix. String of dolphins's growth habit — trailing succulent — sets the pace. String of dolphins is a quirky succulent hybrid with leaves shaped like leaping dolphins. A cross between string of pearls and Senecio articulatus. Mildly toxic to pets like its parents and demands bright light to keep its distinctive leaf shape.

What size pot to step string of dolphins up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. String of dolphins 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 string of dolphins

Spring or summer, while string of dolphins 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 string of dolphins

Repot dry. Do not water string of dolphins 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 free-draining 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 string of dolphins 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 string of dolphins 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 string of dolphins

String of dolphins wants free-draining succulent mix. Cactus mix with 30% extra perlite. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting string of dolphins — frequently asked questions

How often should you repot string of dolphins?

Every 2–3 years, into bone-dry mix for string of dolphins. Repot string of dolphins every 2–3 years into a snug pot of free-draining 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 string of dolphins need?

When is the best time of year to repot string of dolphins?

Should you water string of dolphins after repotting?

No — not straight away. Repot string of dolphins 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 string of dolphins after repotting?

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