Succulents and cacti are some of the easiest plants to keep alive, right up until they're potted in the wrong compost. These are desert and dry-climate plants built to survive drought, and ordinary compost holds far too much water around their roots, which quietly rots them from below. The fix is simple: a gritty, free-draining cactus and succulent compost. Here's what that means and how to pot them properly.
By Kel Dickson, Senior Brand Marketing Manager at Gro Worm, organic, peat-free grower. Reviewed by Brian McCuskey. Updated August 2026.
Why ordinary compost kills succulents
Multipurpose compost is designed to hold onto moisture, brilliant for thirsty summer bedding, disastrous for a succulent. In the wild these plants store water in their leaves and stems and expect their roots to dry out fast between rare downpours. Sit them in dense, water-retentive compost and the roots stay permanently damp, which leads to soft, mushy stems and root rot. Most mystery succulent deaths are really slow drowning.
What makes a good cactus and succulent compost
The key word is drainage. A good cactus and succulent compost is open and gritty, with plenty of sharp material like grit or sand mixed through so water runs straight through and air gets to the roots. It's also lower in nutrients than standard compost, because succulents are slow, lean growers that don't want to be pushed with heavy feeding.
Ours is peat-free and lightly enriched with worm castings, which give a gentle, slow trickle of nutrients and beneficial microbes without the richness that would force soft, floppy growth. It's Soil Association approved and OF&G certified organic. If you're ever mixing your own, a rough guide is around two parts peat-free compost to one part horticultural grit, but a ready-blended mix takes the guesswork out.
How to pot and water them
Choose a pot with drainage holes. Terracotta is ideal because it breathes and dries faster than plastic. Pot the plant so the base of the stem sits at the surface, firm it in gently with the gritty mix, and resist the urge to water straight away; give a newly potted succulent a few days to settle first.
Then water less than you think. Soak the compost thoroughly, let it drain, and don't water again until it's completely dry, often every couple of weeks in summer and barely at all in winter, when most succulents rest. When in doubt, leave it: these plants forgive under-watering far more readily than over-watering.
Christmas cactus and other forest types are the exception
Schlumbergera, the Christmas cactus, is not a desert plant, and treating it like one is why so many end up shrivelled and flowerless. It grows in the crooks of trees in Brazilian rainforest, so it wants more moisture and more organic matter than a desert cactus, and a heavily gritted mix will leave it permanently thirsty.
Use a house plant compost with extra perlite or fine bark mixed through rather than a cactus mix, so it drains freely but still holds some moisture. Water properly through spring and summer whenever the top couple of centimetres feel dry, then ease off in early autumn and give it cooler nights and longer darkness to trigger the buds. The same goes for its relatives, the Easter and Thanksgiving cacti.
When to repot
Repot in spring, as growth restarts, rather than in the depths of winter when the plant is dormant. A root damaged in November will sit wet for months without healing, which is how a healthy-looking plant quietly rots from below over winter.
Most cacti and succulents are happy to be repotted every two to three years, or whenever the plant is visibly lifting itself out of its pot or has stopped growing despite good light. Go up one pot size only, since an oversized pot holds more damp compost than the roots can use. Leave the plant dry for a week afterwards so any broken roots can seal over before the first watering.
Frequently asked questions
What compost is best for succulents?
A free-draining cactus and succulent compost with plenty of grit mixed through. It should let water run straight out and dry quickly, the opposite of what ordinary multipurpose compost does, and be low in nutrients to suit their slow growth.
Can I use normal compost for cacti?
It's the most common way to lose them. Standard compost holds too much water around the roots and causes rot. If it's all you have, cut it heavily with horticultural grit or sand, but a purpose-made cactus compost is far safer.
Do succulents need special compost?
Yes. Their whole survival strategy depends on roots that dry out fast between waterings, so they need a gritty, free-draining mix rather than the moisture-holding compost most other pot plants prefer.
How often should I water succulents?
Only when the compost has dried out completely, often every week or two in summer and much less in winter when they rest. Always water thoroughly then let it drain; frequent little sips do more harm than an occasional proper soak.
Can I make my own succulent compost?
Yes. A rough mix of around two parts peat-free compost to one part horticultural grit works well. A ready-blended cactus and succulent compost takes the guesswork out and gives consistent drainage every time.
How often should I repot a cactus?
Every two to three years, in spring rather than winter, and only up one pot size. Leave it dry for a week afterwards so any damaged roots can seal before you water.
Does a Christmas cactus need cactus compost?
No. Christmas cactus is a rainforest plant, not a desert one, so it wants a house plant compost with added perlite or bark rather than a gritty cactus mix, which would leave it too dry.
Give them the drainage they crave
Repotting your succulents or cacti? Our peat-free cactus and succulent compost is gritty, free-draining and worm-cast enriched, Soil Association approved and made to keep desert plants happy and rot-free.
