sorry for the huge picture.

Fenestraria. Yeah I'm having trouble with mine, too. It looks like you might have a little distortion there from nitrogen fertilizer. Well, offhand...

I think Turface serves better as a top dressing than a growth medium. It has a nice, clean look but a lot of people have complained it seems to work for some plants and fail for others. It holds a lot of water, even though it's coarse enough to allow air around roots. (There was a long discussion of this on Xeric World.) In particular it is definitely NOT the culture equivalent of grit or pumice. But if it works for you, I'd imagine there might still be a way to make it work. Maybe.

To the problem at hand... I grow about 500 C&S plants, but my mesemb skills are still pretty basic. However... I have a great recommendation for a freely available guide to their culture, Steven Hammer's "The New Mastering the Art Of Growing the Mesembs". He has a section on Fenestraria and a lot of general mesemb guidelines. I'll include a link.

Good luck! These are fall-winter growers and summer dormant, so keep that in mind. This is the season to water them just enough to hydrate the roots, and little to no feeding. My problem is, I water and "fertigate" generally, and fail to segregate my winter-growing mesembs to protect them from wrong-season water and feeding.

Here is a link that might be useful: Steven Hammer's, The New Mastering the Art Of Growing the Mesembs

"It holds a lot of water, even though it's coarse enough to allow air around roots."

My understanding of turface: For non-succulents this is actually a really good thing. The air flow prevents rot; the water prevents root dieback.

It sounds like it still holds too much water to use in that proportion for a succulent though. I'm thinking the turface should be like, 1/3 to 1/2 of the potting mix's composition, not 3/4.

Also commercial cactus soil is usually garbage and just peat that they're calling 'cactus soil' because there are no regulatory commissions for dirt so they can really just say whatever they want. I'm thinking like 1/3 turface, 1/3 pumice, 1/3 gravel/bark might work better?

In regards to mesembs, I don't understand how they work either, as indicated by my thread on Faucarias. Also my Trichodiadema bulbosum suddenly has leaves again after losing them all because I kept it too dry? dark? all winter. Are those even deciduous?

Hi amccour: "My understanding of turface: For non-succulents this is actually a really good thing. The air flow prevents rot; the water prevents root dieback."

I'm sure this does work for a lot of plants. Growing medium is such a personal thing, interacting with your climate, humidity, air flow, watering habits... and plant idiosyncrasies. For sure, the air flow sounds like a plus.

When the subject of Turface came up before, some growers noticed a little algae growing on the bits of Turface at the top of their pots. This was interpreted by many contributors as evidence of less-than-ideal conditions for some succulents.

I would add my vote to your suggestion to keep the "cactus mix" very low (1/4 at most) and add a bunch of pumice (and/or perlite, grit) instead of 3/4 Turface (a brand name for sintered clay). Alternatively, in my area (Southern California), many growers I admire use 100% pumice, with great results.

I use 2 parts pumice, 2 parts perlite, optional 2 parts grit (very coarse granite sand), 1/2 to 1 part organics ("cactus mix", "potting soil", commercial mix, or coir) and fertilizer.

dcelzinga: you nailed it with the nitrogen fertilizer. I flushed it yesterday and now it looks better and where I live growing season is just starting. viva colorado.

in a humid climate turface might not make sense because of its water holding capacities but on the high plains in colorado where it is hot, dry and there are fierce dry winds, you want to hold on to all the moisture you can get.

I would love to get my hands on pumice for my soil mixes but i cant find it anywhere around me and I work at a garden center. go figure.

I read that link you posted too. Jesus these plants are tricky. but i have yet to kill a plant i didnt neglect.

Hi steezeven: I hear you... for some reason it can be hard to find pumice in some areas. One trick I learned from a friend is to shop at a feed store. Look for Dry Stall (a lightweight, granular conditioner for horse stalls). This is actually small-size pumice. (I actually like the small grain size.)

Some bags of Dry Stall have a lot of "fines" (dust), but it's inexpensive... and it's potentially available wherever horse supplies are sold.

You mention neglect... yeah, part of my problem is I have to leave town for weeks at a time. I cross my fingers, set the sprinklers, and hope for favorable weather.