Succulent and cactus care in the UK

A guide to watering, pot material and drainage for succulents and cacti kept in British homes, where lower light and cooler rooms mean most of the advice written for warmer climates does not quite apply.

Read more plant care guides for other houseplants

How often to water succulents and cacti through a British winter

Most watering advice for succulents and cacti comes from guides written in the US or in warmer parts of Europe, where a centrally heated British winter does not exist. Translated into a UK home between October and March, that advice waters far too often.

Why the usual advice runs too wet for a British winter

A succulent or cactus slows down when the days get short, whatever the room temperature is doing. Growth stops, the roots take up very little water, and whatever is left in the compost sits there. Indoors, with the heating on and the light through the window weak and grey, that damp compost dries far more slowly than it would in a sunnier, drier native climate, so a schedule built for those conditions leaves the roots sitting wet for weeks longer than they can tolerate.

What watering once a month or less actually looks like

From roughly November to February, check the compost. Push a finger in to about 4 to 5 cm; if it is still damp at that depth, leave it. Once it is dry right through, water thoroughly until it runs from the base of the pot, then don't touch it again until the same test says it's dry. For most succulents and cacti in an unheated or moderately heated British room, that works out to once a month or less, sometimes closer to every six weeks in a cool spare room or hallway.

When to water more often again

As the days lengthen from around March, growth picks back up and the compost starts drying faster between waterings. That's the point to move back towards checking every two to three weeks.

Why succulents stretch without enough light

Succulents and cacti come from places where sunlight is intense and the day is long, and an indoor spot has to get as close to that as a British home allows. A south-facing windowsill is the one most homes have that comes close, because it carries direct sun through the bulk of the day.

What happens without enough light

A succulent kept too far from the glass, or set on a dimmer sill, starts reaching for what light there is. The stem lengthens between each leaf, the leaves themselves thin and space out, and the tight, compact shape a succulent is bought for loosens into something leggy and pale. This is called etiolation, and it doesn't reverse: a stretched stem stays stretched even once the plant is moved somewhere brighter.

No pot changes this. Moving a stretching succulent into a bigger pot, a different material, or one with better drainage addresses none of it, because the plant isn't short of soil or short of air at the roots. It's short of light, and that's a separate problem that only a brighter window, or a grow light, can put right.

Pot material	Drying speed	Watch out for	Suits
Terracotta (unglazed)The material most forgiving of a slightly heavy hand with the watering can.	Fast. The unglazed wall lets moisture pass through it as well as evaporate from the surface	Can look dry on the surface while still damp lower down in winter	Readers who tend to water on a schedule
Glazed ceramicNeeds a reliably gritty mix and a drainage hole, since the pot itself will not help the soil dry.	Slow. Glazing seals the surface, so water only leaves through the drainage hole and top evaporation	Holds moisture longer, so the same watering routine as a terracotta pot can mean sitting wet soil	Readers who water sparingly and want a pot that does not fight gritty soil
PlasticLighter to move and less likely to crack in a cold porch or an unheated room.	Slow. Plastic is non-porous, so drying depends entirely on the drainage hole and the room's air	Dries at roughly the same slow rate as glazed ceramic, so overwatering shows the same way	Cold windowsills, hallways and anywhere weight is a concern, provided the mix is right

This is general guidance on how each material behaves, not a tested comparison of specific pots.

Why a drainage hole and a gritty mix are not optional

A succulent or cactus kept in a pot with no way for water to leave will eventually rot at the roots, however careful you are about when you water. That makes the pot itself the first decision. A drainage hole paired with a soil mix that lets water pass through quickly is the baseline these plants need, and neither one on its own does the job.

What a drainage hole does that a pot shape can't

Water that reaches the bottom of a pot has to go somewhere. With a hole, it runs out and the soil above it dries at a rate the roots can tolerate. Without one, that water sits in the lowest layer of soil with nowhere to go, and the roots sitting in it stay wet long after the surface looks dry. Succulent and cactus roots are adapted to brief, infrequent soaking followed by a long dry spell, so a pot that keeps them damp works against the plant.

Why a layer of gravel at the bottom doesn't fix a sealed pot

Putting gravel in the base of a pot with no drainage hole is a common workaround, and it does not behave the way it looks like it should. Water does not drain through the soil into the gravel the way it drains through a hole in the bottom of a pot. Instead, the soil above the gravel has to become fully saturated before any water moves down into it at all, which means the roots sit in wet soil for just as long, if not longer, than they would without the gravel. The pot looks like it has drainage. It behaves as though it doesn't.

A liner pot with a drainage hole, set inside the sealed decorative pot, solves the same problem properly: water runs out of the liner and into the base of the outer pot, where it can be tipped away.

What a gritty soil mix is actually made of

A gritty mix is ordinary potting compost opened up with coarser material so water moves through it. A typical mix combines:

Ordinary peat-free potting compost, as the base
Horticultural grit or coarse sand, to create air gaps and speed drainage
Perlite, for the same reason in a lighter form

Compost on its own, even in a pot with a hole, holds water around the roots for longer than these plants can tolerate. The grit is what stops that happening. How the material a pot is made from interacts with that mix is covered in the planter material comparison, since a porous pot and a gritty mix do more together than either does alone.

Moving succulents and cacti outside for summer

A succulent or cactus that has spent the year on an indoor windowsill can do well outside for a British summer, but moving it straight into full sun is the surest way to scorch it. Light through glass is weaker than the same sun falling directly on a leaf, so the plant needs a week or two to adjust before it can sit in a south-facing spot all day.

Hardening off before the move

Hardening off means introducing a plant to stronger light and outdoor air gradually. Start by placing the pot somewhere shaded and sheltered outside for a few hours a day, then increase the time and the light it gets over one to two weeks. Watch the side that faces the sun for white or brown patches, which is scorch. If you see it, move the plant back to partial shade and slow the process down.

What changes about watering outdoors

Outdoors, the soil dries faster because of wind and direct sun, so a succulent that needed water once a month on an indoor windowsill may need checking more often once it's moved out. The rule stays the same: let the mix dry out fully before watering again, testing with a finger a few centimetres down. Rain is the bigger risk once a pot is outside. One without a drainage hole collects rainwater at the base and sits wet for days, which is the fastest way to lose a succulent or cactus. A pot with a hole, covered in the guide to drainage, lets that water escape.

Terracotta dries faster than glazed ceramic or plastic, which helps outdoors where rain adds moisture you can't control. If you're choosing a pot for the summer move, the comparison in the guide to planter materials covers how each one behaves once it's exposed to weather.

When to bring them back in

Most succulents and cacti are damaged once night temperatures drop below 5°C, a point that arrives earlier for a plant on a balcony or doorstep than the daytime weather suggests. Check an evening forecast, and bring the pot back in once nights are regularly close to that mark. Move it back gradually, giving it a few hours near a bright window before returning it to its usual spot, so it isn't shocked by the change in reverse.