String of Dolphins (Senecio peregrinus) is one of the most charming trailing succulents: fleshy leaves shaped exactly like tiny leaping dolphins, strung along thin stems that cascade from a hanging basket. It is a conversation piece — guests always notice the dolphins — and it is a relatively easy succulent once you understand that it wants sun and very little water.
It is a hybrid, and like many string succulents it has a weak point: the stems rot quickly if the soil stays wet, and the leaves shrivel if it stays dry for too long. The balance is bright light, a very free-draining mix, and watering only when the soil has dried out completely. It is toxic to cats and dogs if eaten, so hang it out of reach. This guide covers light, watering, humidity, temperature, soil, repotting, feeding, propagation and the common problems that show up when something is off.
String of Dolphins at a glance
| Care factor | What this plant needs |
|---|---|
| Botanical name | Senecio peregrinus |
| Light | bright direct |
| Water | every 2–3 weeks; let soil dry fully |
| Humidity | low |
| Temperature | 60–80°F (16–27°C) |
| Repotting | every 2–3 years |
| Pet safety | toxic to cats and dogs |
Light
Give your String of Dolphins bright direct light. A spot near an east- or west-facing window is usually ideal, or a metre or so back from a bright south-facing window. In the right light the plant grows steadily and keeps its colour; in too little light growth turns weak and stretched, and the plant loses the look that makes it worth growing. Our grow-light calculator can help work out whether your spot is bright enough.
Give it bright direct sun — a sunny south- or west-facing window is ideal. Sunlight keeps the dolphin leaves plump and compact and the stems from stretching; in low light the stems grow long and bare, the leaves flatten out, and the dolphin shape fades. If the top of the pot is shaded by the hanging basket, the crown will thin — make sure light reaches the soil surface.
Watering
Water: every 2–3 weeks; let soil dry fully. The golden rule is to check the soil before you water rather than watering on a fixed day — push a finger into the mix and water thoroughly only when it has dried to the depth the plant prefers, letting the excess run out of the drainage holes. Then empty the saucer so the plant never sits in standing water. Our watering calculator gives a starting point for your pot size, and the watering schedule generator can help you build a routine around it.
Water only when the soil has dried out completely — every 2–3 weeks is usually right. The dolphin leaves are the gauge: plump leaves mean the plant is hydrated, while wrinkled, deflated leaves mean it is thirsty. Water thoroughly when you do water, let it drain completely, and never let the pot sit in water.
Humidity and temperature
String of Dolphins needs low humidity and temperatures of 60–80°F (16–27°C). Humidity is the care factor most homes get wrong: heated indoor air in winter is far drier than most houseplants like, and the first sign is usually brown, crispy leaf edges. Grouping plants together, a pebble tray under the pot, or a small humidifier near the plant all help; a humidifier is the only method that reliably lifts humidity enough. Misting does very little — the water evaporates in minutes. Our humidity and temperature checker can tell you whether your room suits this plant.
Low humidity suits it — this is a succulent, and it is perfectly happy in ordinary dry household air. High humidity and poor airflow are more of a problem than dry air, so do not mist it and do not keep it in a steamy bathroom.
Soil and potting
Indoors, String of Dolphins needs a rich but free-draining potting mix. Standard potting soil on its own can hold too much water and compact over time, so mix it with perlite and orchid bark to keep air around the roots while still holding some moisture. A pot with drainage holes is not optional; without one, water has nowhere to go and root rot follows. Our potting-mix calculator can work out the parts for a homemade mix for your pot size.
Use a very free-draining succulent mix — cactus soil with extra perlite or coarse sand. The mix must dry out quickly after watering, because wet soil around the thin stems is the fastest way to lose this plant. A shallow pot with drainage holes suits it better than a deep one.
Repotting
Repot every 2–3 years, in spring, or sooner if roots are circling the drainage holes. Move up only one pot size — a pot that is too big holds wet soil the roots cannot use, and that is a fast route to rot. Our repotting calculator can help you work out the next pot size and how much fresh mix you will need.
Repot every 2–3 years in spring, moving up only one size. String of dolphins has shallow roots and dislikes disturbance, so repot only when the roots genuinely fill the pot, and handle the trailing stems gently — they snap easily.
Feeding
Feed during the growing season, in spring and summer, with a balanced liquid houseplant fertiliser at half the strength on the label, roughly once a month while the plant is actively growing. Do not feed in autumn and winter when growth slows. Always follow the directions on the label — more fertiliser is not better, and excess salts build up in the soil and burn the roots, which often shows up as brown leaf edges. If you have been feeding heavily, flush the soil with plain water occasionally to wash the salts out. Our fertiliser calculator can help you get the dose right.
Feed lightly — once a month at half strength in spring and summer is plenty, or even less. Succulents need very little food, and overfeeding produces soft, stretched growth.
Propagation
String of dolphins propagates from stem cuttings. Take a cutting a few centimetres long, let the cut end dry for a day or two, then lay it on moist succulent mix — it will root at the nodes within a few weeks.
You can also lay a trailing stem across the soil surface of the same pot, where it roots at the nodes and thickens the plant. Keep cuttings bright and do not overwater while they root.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| Slow growth | Too little light or pot-bound | Give more bright light; repot if pot-bound. |
| Pests | Check undersides of leaves regularly | Inspect leaf undersides weekly; isolate and wipe or shower the plant. |
| Yellow leaves | Overwatering | Let soil dry more between waterings; check drainage. |
Slow growth
Likely cause: too little light or pot-bound. First check the light: move the plant a little closer to a bright window and see whether new growth picks up over the next month. Then check whether it is pot-bound — roots circling the drainage holes mean it is time to repot into a pot one size larger with fresh mix. Do not try to force growth with extra fertiliser; a plant that is short of light or root room will not use it, and the salts can burn the roots.
Pests
Likely cause: check undersides of leaves regularly. Inspect the undersides of the leaves every week, especially in warm weather, and isolate the plant at the first sign of trouble so pests do not spread to neighbours. Wipe the leaves with a damp cloth or give the plant a gentle shower, and repeat weekly until the pests are gone. Our pest identifier helper can help you work out what you are dealing with before you treat it.
Yellow leaves
Likely cause: overwatering. Yellow leaves most often mean the soil has stayed wet for too long. Let the top of the soil dry out before watering again, check that the pot drains freely, and remove leaves once they are fully yellow. If several leaves yellow at once, check the roots — soft, black roots mean rot, and you should cut the rot away and repot in fresh mix. Water less in winter, when the plant grows more slowly and the soil stays wet for longer.
Frequently asked questions
How often should I water String of Dolphins?
Every 2–3 weeks; let soil dry fully. Check the soil with your finger before watering rather than watering on a fixed day — pots dry out at different rates depending on light, pot size and the season.
How much light does String of Dolphins need?
It needs bright direct light. Too little light gives weak, stretched growth, while harsh direct sun can scorch the leaves, so a bright spot out of direct midday sun suits most plants in this guide.
Is String of Dolphins safe for cats and dogs?
According to the data used for this guide, this plant is toxic to cats and dogs. Keep it out of reach of pets that chew plants, and if a pet eats any of it, contact your vet.
When should I repot String of Dolphins?
Repot every 2–3 years, in spring, or sooner if roots are circling the drainage holes. Move up only one pot size so the fresh mix does not stay wet for too long.
Why are my string of dolphins' leaves flattening out?
Flattened leaves usually mean too little light — the dolphin shape develops best in bright sun. Move the plant to a sunnier window, and new growth should come through with the proper dolphin shape. Old flattened leaves will not change back.