What type of soil should I use for my cacti?

Cactus soil needs to be well-draining, otherwise they rot easily. The ideal is to use a mix of regular potting soil with coarse sand or perlite, something like 70% soil and 30% sand. I do this at home and it works well - mine have never had problems with excess moisture. If you can, also add a bit of fine gravel at the bottom of the pot to improve drainage even more.

Perlite is genuinely essential, but you don't need to be so strict about the proportions - I'd say the most important thing is making sure the drainage is really, really good, so mix coarse sand with some perlite (or even small stones) into normal soil, and let the cactus breathe. What people usually get wrong is thinking 30% is enough; if you see that water takes ages to drain from the pot, add more sand next time. It also depends on the species and the humidity where you live, but generally speaking the better the drainage you give the soil, the harder it is for it to rot.

Don't even think about using regular garden soil or potting soil - it gets waterlogged and your cacti will rot in no time. What works well is mixing regular soil with plenty of sand or perlite, but if you want an extra trick, add some activated charcoal to the mix - it helps prevent fungal issues and root rot, especially if you're not super careful with watering.

What nobody's mentioning is that the type of cactus really matters too - some species tolerate more moisture and others basically die if the soil stays wet for more than a few days. But if you want something that works for most, the golden tip is to test drainage before planting: put water in the empty pot and see if it drains quickly through the bottom. If it gets waterlogged, add more sand or perlite to the mix until it's right. Another thing that helps a lot is using terracotta pots instead of plastic - terracotta breathes and dries naturally, so even with less-than-perfect soil the risk of rot drops significantly.

I did some different tests with my cacti and what really worked was adding a lot of fine gravel to regular soil - like one part gravel to two parts soil - because it drains super fast and the pots never get too wet. What really matters is having holes in the bottom of the pot and watering only when the soil is completely dry, because no mix can save a cactus that gets water every week.

The most common mistake is thinking any soil will do - cacti need brutal drainage, so forget everything dark and dense. What actually works is taking regular potting soil and mixing it with coarse sand, perlite, or even fine gravel, but here's the detail nobody mentioned: add a bit of activated charcoal to the mix, like 5-10% of the total. The charcoal absorbs excess moisture and prevents fungi and bacteria that rot the roots when the soil gets a bit damp. After you plant them, let the pot sit for a few days before watering - it gives the soil time to settle and helps fill the empty spaces properly.

The most practical thing is to buy ready-made soil specifically for succulents and cacti - it comes with the right drainage and saves you the hassle of getting the proportions right on your first try. If you'd rather mix it at home, the real secret is never letting water sit: put a pot with nice big drainage holes at the bottom, fill it with gravel or broken terracotta pieces, then add soil mixed with coarse sand or perlite. Always check that it drains well when you water - the water should go through almost right away, otherwise it's too compacted.

What I do at home is just add a lot of coarse sand to regular potting soil, without overthinking exact proportions - the important thing is that the pot drains fast, otherwise the roots rot in days. After I plant, I check if water comes out the bottom quickly; if it stays waterlogged, next time I add even more sand to the mix.

I'd say drainage is really crucial, but what nobody here mentioned is that soil composition varies quite a bit depending on what species of cactus you have. A desert cactus needs something completely different from a tropical rainforest cactus, and if you mix everything the same way you can run into problems. The important thing is knowing first what you're dealing with.

Otherwise, I agree that plain potting soil alone is a guaranteed disaster. What I do is mix potting soil with coarse sand in a ratio that leaves the substrate really crumbly - like half and half, without being too precise about it. Perlite works well, but since you mentioned the budget side of things, coarse sand or even diatomaceous earth (if you can find it) do the job just as well. The big warning that's missing is: whatever mix you use, test it first on a plate - water it well and see how long it takes for the water to drain. If it stays waterlogged for more than 5 minutes, your ratio is wrong. A lot of people just trust the theory and then get a nasty surprise when the cactus rots despite everything being "correct".

When I mix soil for cactus, I put in quite a bit of gravel or coarse sand, but there's one thing nobody mentioned: the pot really needs proper drainage holes, not just some tiny hole. A bad watering can also ruin everything - it's better to water sparingly and let it dry out well between waterings than to have the best soil in the world with constant moisture.

What really makes a difference is having decent drainage holes at the bottom of the pot - without that, no soil mix will save you! I had some cacti that were dying and discovered the pots were basically sealed capsules, so I started using terracotta pots with actual holes and a simple mix of regular potting soil with about 40% coarse sand, and it changed everything. Water drains quickly and the roots do so much better, without that waterlogging that was rotting them in weeks.

What nobody mentioned is that it's worth saving leftover used soil and reusing it - cacti aren't that picky and a recycled mix with extra perlite drains really well. Oh, and if the pot doesn't have a drainage hole, forget it, the best soil in the world won't help.