Perhaps this thread may be useful? How much gypsum in gritty mix?

My understanding is gypsum is there to add calcium to the mix. But many growers are using Foliage Pro or similar fertilizer with micronutrients, which I believe includes calcium? I would confirm that!

The poultry grit I use comes with a bit of added calcium, so I haven't really bothered to look into gypsum at all. And I'm not so sure others are really using it that much for succulents either.

If you're looking to mitigate nutrient deficiencies, I would expect that the gypsum or whatever amendments you want should be mixed in uniformly. If I don't exactly understand what it is/why it is required/how much my plant is 'missing', then I prefer not to add it to my own pots. =)

I'm in the gypsum phase too! I have seen that Al recommends including it in gritty mix even for those who are using Foliage Pro. My question is, since it breaks down over time, how/when should it be replenished?

I'm not sure anybody here is bothering anymore to add gypsum for succulents... Questionable if the impact is worth the effort?

Or maybe I haven't seen it discussed in a long time.

Oh, man, those were the days, eh. I once spent weeks completely nerding out on Al's long treatise on water movement in containers. If you read carefully and keep an eye on the dates of the discussions, he started out with adding DE or what-not. Eventually, he simplified the gritty principle to this: get the gritty mix, use a balanced fertilizer with micronutrients.

Balanced meaning 3:1:2, not 1:1:1 which is actually high-phosphate.

I spilled a new bag when I got it home, and subsequently decided to give up on it entirely and just take my chances living gypsum free.

That must have been quite the mess...

Not as bad as spilling a huge bowl of pumice on my hardwood floors. It was a nightmare. But who can live a pumice-free life? Gypsum, meh.

We were going to put hardwood in our loft... and then I got really into growing succulents and that idea got tossed very quickly. Carpet it is! Aha.

You guys crack me up. I have no space for a potting bench, so I do all my plant work on the stone/tile living room floor. (Turface. Everywhere. Plus pine bark dust, potting soil, mesh clippings, etc.) I won't be surprised if things start growing from the cracks soon. Actually it works out fine, I just sweep a lot. ;) And it helps that we have a roomba!

I think the issue is that pumice / grit will scratch the heck out of hardwood floors. Stone / tile isn't even remotely similar.

(I like how this topic has finally been revived and yet nobody has an actual answer, lol.)

Pagan, is this mix for cactii or for Succulents in general?

For container plants in general. Check out the link ewwmayo posted above and with a little arithmetic, it's easy to work out. I just made a ballpark calculation because using cups and tablespoons to measure anything is nothing short of medieval.

Again, you don't need gypsum if you use fertilizer with micronutrients already in it.

Oh wait. Did you mean the gritty mix itself, Helen? I only use it for cacti and succulents. For water-hungry tropicals that go limp when dehydrated, I would suggest using regular potting soil unless you want to water everyday or maybe even twice a day.

But doesn't Pagan and Mediaeval go together? lol

Really I'm trying to read anything that comes up on mix for Succulents, not cacti if they have different nutrient needs and not for general plants. It's confusing with so many options and opinions. But I'll plod on asking the odd question.

I've done some propagating using perlite only, and decided to buy some C&S potting mix with perlite 40:60 for regular potting until I work out what I might want to try out (mainly to get them looking gorgeous like I see here and other places, but also to grow touchier species).

My next question was to be what do people use to give them nutrients or fertilizer when using "stuff" eg grit, perlite, stones, coir etc. with no nutrients.

But I was getting stressed coz I want to understand it all now! lol. Hence the C&S perlite mix.

Why, they do! lol But only just, since the pagans predated the medievals.

One of the upsides of using gritty mix is that you have full control of the nutrients that go into your plants---the substrate is basically just storage to hold the stuff for plants to gradually absorb. Soil-free substrate has nothing so the same upside is also the downside in that you have to control what goes in.

The shortcut that also have predictable results are fertilizer solutions that also have micronutrients added. You'll know by looking at the label. For example:

I bet there are fertilizers for residential use that are similarly formulated available for growers in Australia.

I know Bunnings has what seems thousands. Thanks heaps pagan. I shall puruse the fertilizers tomorrow when I get the C&S soil, more perlite etc.

Mmm. Pagan, preditor of the mediaevals. ;D

@ Pagan

Regarding the 1 Tbs. gypsum to 1 gallon gritty mix suggestion: Should that be mixed uniformly before potting, or sprinkled on top and watered in? (Also relevant to replacement of gypsum after a year or so. Should the plant be re-potted, or can it just be watered back in, since the rest ((except for the bark)) is non-organic?)

Just mix it in. When repotting, just dump the pot entirely, inspect the roots and clean up any dead ones, remix your soil, then repot. =)

My understanding was that Al no longer regards gypsum as an essential ingredient in gritty mix if using 1/4 strength Foilage Pro... did I get this wrong?? D:

No, you didn't get it wrong. It's redundant if you're already using fertilizer with Calcium in it.

I was actually looking at how to use gypsum to help protect my Japanese Maple bonsai from the horrifically hard water we have in Phoenix.

I would imagine it also would help protect cacti and succulents as well.

The web page I read it from mentioned adding it to the soil while potting up but I was hoping for a water mix-in recipe as I use a very gritty pumice/akadama soil mix. 1 Tbsp/gallon! Thanks all!