I would like to ask everyone to please stick to the topic and focus on soil for cacti and succulents. Any other questions should go elsewhere on the forum, for example a new thread about how to start prickly pear cactus seeds, which could be useful. Stuff like that can also be posted as an addition to the general chat thread here:

The thread "Cactus and succulents chat" in Cactus and Succulents forum

I'm not normally much of a stickler for staying on topic, but this is one of three threads "stuck" to the top of the forum, and I really would like to keep it laser-focused if possible.

I moved my succulents from ordinary potting soil like a month ago/ maybe 2 to roughly
50% perlite 25% chopped fall leaves (what I had overly available), and 25% potting soil
They appear to be doing better and have been putting out new growth and have overall bigger leaves

My cactuses definitely needed the change in soil to a less water retaining one since it was starting to get some fungal spots

I own a plant server on discord and we often get a lot of brand new growers who join for troubleshooting and care advice, and since cacti and succulents are so fascinating and easily obtainable most of em show up with plants from walmart and the likes just potted up in compacted or soggy peat from every day watering- Pretty much sold to them on death row if they don't know how to do home-arrival care.

My mods and I find that explaining the details of soil mix additives and whatnot can be really overwhelming for people who've just bought their first plant and arrive like "This is my new son, I've had him for two hours and would give my life for him, how do I keep him alive"- You know the ones, impulse buys because the plant is pretty, even though they know n o t h i n g about plants. Anyway a lot of the times the most convenient option is to suggest a brand of pre-mixed succulent soil instead of going into the science of mixing adequate grit- Which is difficult, there's not a lot of pre mixed soils that meet our standards enough to recommend, but we have ONE brand that we hold above all others, and that would be Bonsai Jack's succulent and cacti soil, it's composed of 33% Pine Coir, 33% calcined clay and 33% Monto Clay, it's a little on the pricier end, but a little goes a long way and its reaaally good for making sure new growers don't struggle so much with rot.

I use it in my own cacti and succulent collection, as well as emulate it when I'm making my own mix, it's a really fantastic gritty mix because I live in a really swampy part of Texas where the humidity is always INSANE so its been the only thing that keeps my plants happy really- My server members and I pretty much deify Bonsai Jack, we'd have a shrine if we could lol

I sow in small containers, maximum 4x16 inches, 1.5-2 inches deep, drainage. I keep up to two months relatively closed, sometimes airing for an hour a day. I add water when the soil dries out once a week, or drop fungicide just in case - at the same time and water. But here's an open container with such coarse sand, peat about 40%, despite this, after watering the top layer after two days dry. Although the peat helps a little to retain moisture. But he also gets wet bad, only the top 0.15 inches.

That's trying to pick up the size of the sand and that the moisture retained and wetted quickly, in this case, you can add a little peat. Just to darken a little and the young plants are not hungry at all. And so that the algae do not grow. And on light substrates - yes, whether on sand or zeolite, algae appears quickly.

I made my first succulent soil mix in 2020, as I've only had an aloe and its kids, until late Autumn 2019 when I bought a sad-looking little Jade plant from the leftover ruins of a summer display table. I used things I could easily find and were inexpensive, like $ Store bagged potting soil and a couple ingredients from a big box store - soil 3 parts, sand 2 parts, perlite 1 part.
I think the sand may be a bit too fine. The attached photo shows it on a paper towel. However, the little Jade grew enough to take cuttings and they're doing fine in the mix.

Is Orchid Bark good for succulents and cacti? I've been using that heavily in my mixes as a nursery I go uses a mix on their succulents that has heaps of bark and its amazing for keeping the soil loose and free draining, even after long periods of no water.

I guess it would work??

JimsPlants said:Is Orchid Bark good for succulents and cacti? I've been using that heavily in my mixes as a nursery I go uses a mix on their succulents that has heaps of bark and its amazing for keeping the soil loose and free draining, even after long periods of no water.

The only time I use a mix of orchid bark and pumice for my succulents is if they are epiphyllums, since they grow as epiphytes.

But all other succulents, I use cacti soil with added pumice or perlite. Sometimes if I have it on hand I may further mix in kanuma or akadama soil. Got to keep it as gritty and well draining as possible, and always containers with drain holes, not too deep containers.

I have a never ending supply of well composted horse manure[Wife has to many mules] I use it in my garden ,do you think I could use this in my cactus and succulent soil mix. I do not have any plants yet just getting GH ready and reading all the books, just been reading about all the different mix's there are here .Any thoughts

I would think it's good up to about 25% of the total volume, in a mix where about half the total volume is rock (pumice/perlite/gritty equivalent). Never tried myself. I've heard of certain select plants doing great on pure manure, but it's not likely to work out generally. As you might imagine these things are very dependent on the plant.

Thank you Baja Do you think I should mix it with a store bought cactus mix ? I see you use a compost based soil mix. Or just use it straight with inorganic material, my property is on an old sea bed I have plenty of course sand. By the way what do you consider course sand? Thanks

Yes, I think putting in some cactus mix should be fine. You can use the sand on your property if you screen it first to remove the fines. I use a bonsai screen with a 1/10 inch filter but I would think you could arrive at similar results using regular window screen, which is about twice as fine.

Thank you

Starting using Miracle Gro Cactus/Succulent mix usually adding (25% or less) Miracle Gro for containers that contains a lot of perlite. Also, use my yard soil(desert sand) add with compost made for our area(contains a lot of cotton stock/bark). I planted some pots with Miracle Gro Cactus/Palm/Citrus. Cover all soil in pots and garden with free local mulch from our city. From May thru early Sept our average high temp. is 100. So most of the cactus thrive and multiply. Palm trees seem to seed in the pots of succulents. Some of the more delicate succulents are in pots on shelf display which is in shade all day. The rest of the succulents get morning sun and afternoon shade and some the opposite. In the Texas winter storm I lost all my aloe vera, most of my jade, and portions of the 'vining' succulents. Soil doesn't seem to make a difference at least not as much as moisture. I use Shake 'n Feed to fertilize all my plants. I consider myself a Lazy gardener at this time in my life.

So this is the link to the blurb on the soil mix i am going to trial
https://www.etsy.com/uk/listin...
I need to find 2 plants i can drop side by side with my current mix and this mix, hopefully to see if i can ascertain any difference in growth
Anyone have a view on the soil contents?
Steve

Looks good to me, mostly mineral it looks like, you might have to water more often.

I'm still trying to figure this out, because as much as I love everyone's input- I can throw crassula ovatta out my window and as long as I don't hit it with the lawn mower it will grow May to October, even on concrete..
That might be an overstatement, but not by much..

There has got to be an easier way to do this. I have a gbarrage ( a garage full of garbage) with half bags of sand, play sand, pool filter sand, cement gravel, pea gravel, turface, Perlite, vermiculite, peat moss, long fiber spagnum moss, coair,, mulch from every tree on the planet, plus a yard full of dirt and leaf compost. I'm not buying any more varieties or brands Of dirt(ish))... . Not when I just bought 3 x $7 ea 3.5" inch diameter 6" deep Pots of echiveria, grapulatum and sedum that are clearly planted in typical potting soil, peat and perlite

There are Published accepted guidelines for veg gardens, You dig a 1ft cubic hole in the ground, fill it with water as long as drains within A given time frame, you're good.. do we have similar guidelines for succulent soil?

50% bagged potting soil, 50% fine grit of your choice... it's pretty simple. You can get away with shortcuts with easier plants (jade for example) but the more demanding ones will suffer if you don't get the drainage right. I would not recommend using dirt from your yard. Compost from your yard is fine as long as it's mature and insect-free and the particles are roughly the right size (not too huge, not too fine). Try to be consistent so that your watering is the same from one plant to the next.

I'm not sure why you have so many different ingredients in your garage other than lots and lots of experimentation, which should be a good thing in the end, and I would imagine that experimentation must have taught you something about which ones work the best for your plants. When you arrive at a satisfactory recipe, you will use up the bag in due time and have no need for or interest in all the other ones you've collected over time, except insofar as they may be interchangeable. My days of random soil experimentation are mostly over because I arrived at something I like.

I know this wasn't exactly what you asked for, but I hope it helps.

I just did a quick test on my preferred soil mix for potted cacti, agaves, aloes, and etc.

I filled a one gallon pot with my mix (~33% pumice added to a balance ~67% of 'premium' cactus and succulent soil that already has some fraction of pumice [I'd say maybe 10% max]) to maybe 1/2 to 1 inch below the rim of the pot. The pot is a pretty standard black nursery pot with five holes, four on the bottom side and one in the middle of the bottom. I started watering it with a steady but not hard stream of water from a 5/8" hose in the center of the soil, I have a 90 degree ball valve on that hose after the tap that was maybe 25% open. I started seeing water come out of the first hole in about 8 seconds, by 15 seconds there was water streaming out of all holes, the flow of water was never large enough and the soil drainage was good enough to never have water pool on top of the soil. Obviously, if you have larger pots with different numbers of holes the result of this kind of a test will likely change, but it should at least give a sense of how fast water should drain through an effective cactus and succulent soil mix.

I'd say though, that unless you have a giant pot, if it takes more than 1 minute for water to start coming out of the bottom of your reasonably sized pot with a good number of drain holes, then your mix is not fast draining enough.

I have a number of legacy pots - largish pots filled quite a while ago with previous soil mixes when I still used sand and other additives beyond my current mix, or occasionally when I was out of pumice to add and I can say that when I water those they take longer to drain and some will have water pool on top of the soil in the pot for quite a while. I live where generally it is warm enough (and I am likely lucky that plants in these pots are pretty forgiving) for those kind of poor drainage conditions to not be a giant issue - but I definitely take care to not water these pots as frequently as they also do not dry out as fast as my current 'preferred' mix.

I also have some pots that over the last few years have become mostly pumice and roots, those drain super fast and they dry out so fast that I can almost water these pots every day since water retention when it is warm is minimal. Most of these are in my 'need to be repotted or put in the ground' queue.

I would be hesitant to rely on a test involving timing the exit of water because the same soil will behave differently depending on whether it is moist or dry, full of roots or not. Not to discount what Thijs has proposed (and by all means whatever works for you is great), just to mention the other variables which may be involved.

There are 2 distinct steps involved in the process: the wetting of the substrate (this part can be very different depending on existing soil moisture) and the passage of water through the substrate (which maybe ideally could be measured distinctly from some starting point of mostly saturated soil). These 2 steps do not necessarily occur separately, rather blend together as the soil begins rewetting and then sheds the extra water that it cannot take up at that moment, and so forth.

At some level it's important to be aware of these steps and monitor how they play out when you water. For example: how much water does a given container take to go from bone dry to fully saturated? You have to do this in a few distinct watering events spaced a few minutes apart, because it is impossible to go from bone dry to fully saturated in one watering, given good drainage. I did this experiment today with a couple of pots because I had to make up insecticide solution in water and needed to know the volume required. Turns out 2 different 10 inch pots (3 gallon size, approx.) absorbed roughly 1.5 liters of water each. (Mixed metric and English units are a way of life here on the border.)

For what it's worth, the amount of water soil can hold is pretty closely related to the amount of organic material in it. The same stuff that we add to improve drainage (ie. the timely exit of excess water from the soil) also ends up reducing the water holding capacity as well. And thus as a general rule the better the drainage, the more often you would have to water to keep needy plants happy.