Thank you both so much. Baja, for breaking it down- because yes, I'm clearly overthinking it, and there is no replacement for regular monitoring and the skill set that comes with experience..

And Mcvansoest, thank you so much for DATA- because it is good to overthink it! Thank you so much for doing that much analysis. I will Refer to that and I hope to continue the factual basis you started. not only drain times, but ongoing plant results, moisture meter readings and environmental controls- because the only thing I'm sure of is no plant lives in the exact conditions of any other .

I love the smart people on this forum.. I couldn't be more grateful for your expertise data and handholding.

Well I guess I might need to make up some more soil for the cacti and succulents and maybe put some of the Euphorbia in bigger pots just
because of all of this rain!

Okay- its been exactly a week since I decided to go rouge with the bags and buckets of NOT on-the-list substrates and I've learned some things.

Mixes that are mostly non-organic- while they drain beautifully- compress really nasty and hard. We're drowning in NY with 14" of rain in the last 12 days and that will really give you an idea of a long term outcome. If I can't press a bamboo skewer through a seed cell, its not going to be nice for new root development, regardless of moisture content and appropritate drainage.. If it feels like concrete- doesn't really matter if its wet or dry.
SO Im wrong before I even planted anything, in every way except 1/3 each perlite, peatmoss and grit (sand, turface, fine aquarium gravel were the same- however, HD fine gravel was the worst and should be used for masonry applications only- its very angular and locks into place after it settles so the drainage is very poor and it compacts so tight nothing will get through it. I think its meant to do that so weeds cant grow in cracks-very efficnt product.

I didn't want to buy more brand name cactus mix- $6 a lb for "special" dirt/organic mix is not okay in my book when I know Its 3/4 sand, perlite and peat, at a minimum. I investigated it, and it seems like the addition to peat pearlite and sand is really really small wood chips- which makes all the difference. I was unable to find superfine wood chips without screening them myself- but I dug around and found something to lighten the load.
THe one thing that made my mix manageable, given I don't have access to very fine wood chips and wont pay top dollar for it was pulling apart then cutting short the coco fibers from last years Dollar store hanging liners- I pulled it apart first then balled it up and cut it into ~1" lengths that I mixed into my various mixes and ended up with a much more manageable flexible soft substrate that I feel really good about.

I did try trimming short lengths off the edge of the coco liner as is. That doesn't work- very clumpy and doesne't ever come apart no matter how much you mix it. You have to pull it apart first and when its a nice airy mess you can cut it with a scissor and mix it in.

We"ll see how many hundreds of dollars of plants I kill to save $6 of specialty soil - but at least we'll have data!

I have in the last year become somewhat of a convert with regards to the more expensive cactus and succulent soil mixes you can buy at nurseries, I did not think I ever would, but during the pandemic last summer, I wanted to get my two soil components at the same place to minimize the need for me to be out and about, since most of the box stores do not sell pumice (I really do not get why you can get bags full or perlite there, but none of the big box stores here sell pumice), I put in a curbside order with a nearby nursery and they only carried the more fancy cactus and succulent mix (E. B. Stone brand if you want to look it up) in addition to the pumice that I really will not do without. I got two big bags of the fancy C&S soil and used one immediately while the other sat in my shade structure for the summer and did not get used till the fall.

I must say that when I grabbed that second bag I was pleasantly surprised, it is my experience with the cheaper ~$6-7 / 1.5 cu. ft. bags of C&S soil that if you let those sit out here, that in about a month of two when you open it, it has become one caked together hard block that needs a lot of work to break up - suggestive to me of the often forgotten ingredient in those mixes: really badly made compost (sewer sludge). The fancier mix ~3x as expensive was pretty much like I got the bag the day before I opened it rather than 3 months earlier. Though it has sand, it is a minor component and the other components are of relatively reasonable comparative size, whereas in those cheap bags you can find huge chunks of wood and what not. The intrinsic pumice and lava rock components are more significant meaning that I have to add less pumice to get to my desired ratio of pumice to other stuff.

So while it is probably not feasible for me, long term, to keep buying the more expensive stuff - just because I have so many plants to pot up and with bigger pots the amount of soil necessary per plant goes up quickly - but I can see why if you are using it for just a few plants - especially more expensive ones, it could be worth the investment and I will certainly keep buying it when I can.

Im sure that best outcomes do result from commercial mixes- but I'm not willing to concede the average joe can't create an easy equivalent where no part costs double dollar digits per pound. There's no way Id spend half a grand on succuent mix because its spring and I Didnt kill my collection 5 winters in a row and still don't know what best soil feels like in y hand- <-- thats a lotta years of frustration- so forgive me if Im uppity.

Baja was trying to help us unemployed college students, lol, but he's still 1/3 commercial mix- a 6 qt bag costs $10 barely fills a 6" pot- and its mostly pearlite. Whats is the fancy schmancy addition that makes it worth that money?

I think "dirt cheap" should still be a legit expression if you're talking about dirt! It should not be an oxymoron. It can't be this difficult

I think I'm the only person who handled a bagged "succulent mix" and tried to describe it- mine dind't have ANY pummice- it had fine hard new wood chips (1/4" square-ish). THe lady before me had a fabulous outcome with a pumice rich bagged substrate that didnt seem to have any wood at all- so there is clearly more than one way to skin a succulent gardener.

Well I will probably stick with the KISS principle of making up my cacti and succulent soil

Absolutely, I agree that it should not be that expensive, and I was not saying that you should buy fancy commercial mixes, I was just pointing out that there are some that are pretty decent, and that some of the almost dirt cheap ones are actually quite poor in quality. So in that sense you still get for what you pay for.

So, while at least twice as expensive as I would like to pay, the difference between the cost both in time and investment in components, then the need to get those components in the right size (your cutting up coconut material, but sieving out the fines or too coarse parts comes to mind as well) all adds up to something that when all is said and done if you'd put money totals on it, you'd not be as far off the commercial mixes in price than you would think. The willingness or ability to invest your own free time into a project like this maybe something you'd do for free, but for a true cost benefit analysis you should count the time spent as a cost (since at the least that time investment is less time spend doing other more fun (and useful?) things with your plants) and put reasonable money amounts on your components, which will not always be free. I think we'd all be really happy if every plant we have would grow great in a pot to which we just added dirt from the yard, but I can tell you that for most plants that is not the case at least not where I live.

In my case with limited time to spend on my plants period (because of work, the rest of my life, and especially this time of year the 105+ Ts making working outside less than pleasant) makes me want to spend as little time as possible putting a soil mix together. Right now I mix a quarter bag of pumice with a half bag of cactus and succulent soil mix and I am done. I will probably have to go back to the $6-7 / bag mixes because of how many plants need to go from 1 to 2 and 3 gallon sized pots, but I certainly wish I did not have to.

The bagged soil that I use as part of my mix is cheap and local, and it comes with a fair amount of leaf litter mixed in (which I filter out before use). Used alone without that extra step it would be unsatisfactory for succulents. But it has the advantage of being cheap and available and incredibly consistent from one batch to the next. And I can compensate for its shortcomings by mixing in an equal amount of cocofiber and twice as much pumice.

My media mix with 3 major component:
- A. Charcoal from rice husk
- B. Mix of red and black lava rock
- C. Mix of pumice, perlite, and akadama (depends on what available)
- some compost and small amount of balanced fertilizer

The mix will be 2 cups of A + 2 cups of B + 2 Cups of C + 1/2 cup of compost and 1/2 spoon of fertilizer, so far the succulents are quite happy with this mix

I understand that we want our media mix to be porous, not soaky during watering to prevent root rot from happening. Assume we have achieved the porosity that we want, my question is, do we want the media to retain the remaining water and humidity as long as possible or to dry out as soon as possible ?

I am in the assumption that I want the media to keep the humidity for long, so we don't have to water that often => Any suggestion and insight on this statement is highly appreciated, as this will decide my future media mix

I measured all the media in terms of how much and how long they can keep water, I fill in all the media in separate pots with the same volume, weight them, then soaked with water for a few minutes, after the water stop dripping, I record their weight again, then I put all those pots in the place where I keep the cactus for 24 hours and then I made a last measure on the weight.
Below are the comparison chart for references:



The size of the Akadama is the largest, then it is quite normal for akadama to retain less water due to its surface area. In average 48% of the water evaporates in 24 hours, then I will assume the water will completely dry in 2 days. How long we want the media to keep the humidity will decide what material to use.

Going out to the store and buying a perfect mix, probably with an exact correct slow release fertilizer is lovely and efficent and reasonably priced when you consider what we pay for plants and pots. Its definately the right way to goo. But, when you're finally good at keeping them alive and happy, you have the water and the light just right and your collection is now hard to count, and cubic ft packages become necessary.. it's time to DIY a dirt recipe

Kaktus said:I understand that we want our media mix to be porous, not soaky during watering to prevent root rot from happening. Assume we have achieved the porosity that we want, my question is, do we want the media to retain the remaining water and humidity as long as possible or to dry out as soon as possible ?

I am in the assumption that I want the media to keep the humidity for long, so we don't have to water that often => Any suggestion and insight on this statement is highly appreciated, as this will decide my future media mix

I measured all the media in terms of how much and how long they can keep water, I fill in all the media in separate pots with the same volume, weight them, then soaked with water for a few minutes, after the water stop dripping, I record their weight again, then I put all those pots in the place where I keep the cactus for 24 hours and then I made a last measure on the weight.
Below are the comparison chart for references:



The size of the Akadama is the largest, then it is quite normal for akadama to retain less water due to its surface area. In average 48% of the water evaporates in 24 hours, then I will assume the water will completely dry in 2 days. How long we want the media to keep the humidity will decide what material to use.

In your area, what you need is faster dry out time. Your humidity levels daily are always higher. Akadama is okay, I have used that.I actually like it very much.

For example, in Jakarta, your average humidity level is at 82%, in my area, our humidity levels is at 10 to 20%...Do not confine your mind to just the dry out period of your media, consider too the water content of the air around the plants. That is why you got to keep them in drier, faster draining media on your side. I do not know which one is your home city in Indonesia, but pretty much, your country has across the board humidity levels due to the archipelagic nature of your location, surrounded by the sea. All the gritty materials you showed above are good to use, either one will be okay..so use smaller containers too depending on the size of your plant's rootball.

Ok, I will keep akadama then, I thought if it is of no additional value, then I will not use it, as akadama and perlite are much more expensive than other materials

I had never heard of "akadama" so I will have to check it out!

Received my latest potting mix delivery. Time to start the repotting (it's Florida, I can repot almost year round) 60% perlite, 20% coir, 20% finished compost plus balanced time release fertilizer with minors.

My lithops seems to like 100% coarse sand. They also do well with bonsai jack gritty mix plus sand and only about 10% potting or succulent mix.

If I grew anything inside under lights it would be Lithops. Very tough to grow here outside in our humidity.
But think of the collection that you could have, you could put 20 different ones in the space of one potted houseplant.

My last lithops die last week, not going to grow them for the time being, not suitable for our climate here, grew them from seeds, after 19 months, the size can hardly reach the size of a soya bean, just read the notes from Baja that they go dormant in summer, no wander mine can not grow, dormant for the whole year..

I'm not like most on here, my mix is more complex and I do not use any overseas imports, including coconut coir. I use ingredients that are found closest to home. I do use a little peat, but only the minimum needed. I keep my peat use down by using two local ingredients, ground Douglas fir bark and worm castings. I have done lots of research into the environmental impacts of peat vs coir. If you want to know more about that research I will share on a separate thread to keep this one more on topic.

The only other comment I have about peat is, I have never found it will repel water if the proper amount drainage is used. I find by adding enough drainage you prevent the peat from clumping together and repelling the water. Those clumps are impenetrable. By allowing plenty of space for the water to flow through the soil, even when it is bone dry, I provide peat the opportunity to absorb water.

Over the years I have developed two different mixes for my succulents and succulent like plants. One is 75% drainage matter to 25% organic matter and the other is 60% drainage to 40% organic matter. My drainage is a mix of Perlite, Pumice, Turface and Grit. I only use perlite, because it keeps the weight down and is cheaper than using just pumice. My organic matter is a mix of ground fir bark, worm castings and peat.

I use the 75:25 as my go to succulent and cactus mix. I found some would prefer more organic matter of the 60:40 like, Monkey Tail Cactus, some aloe, sansevieria, kalanchoe, and many non-succulents like citrus and mediterranean plants.

I also add Leonardite Powder (Humic Acids), mycorrhizal fungi, and diatomaceous earth to all of my mixes. Humic acids are great at stimulating root and plant growth, as well as stimulating beneficial fungi and soil microorganisms.

Like I mentioned at the beginning even the most simple recipes can work. I have even successfully grown succulents in mix of worm castings and perlite only, not that I would recommend starting there.

I'm a succulent newbie. Just found a recipe and wondering if it's okay:
1 pt. perlite, 2 pts. grit or course sand, 3 pts. garden soil. I'll be doing a rock garden. I will also check out all the info within this thread.

I was wondering if there's such a thing as an all purpose mix that can do well in a multitude of zones with a variety of plants. Or is that too much to wish for?