Lithops question

[Kamos]

Hi everyone,
I just had a small pot of 4 L. aucampiae fall off the window sill. They seem to be undamaged from the fall, but as I
was repotting them, I noticed the roots were very dry. I gave them a good soak a little over a week ago, and the
leaves/bodies are firm, but the under-side of one of them is wrinkled. I'm not sure what I should do. Should I water
them and risk splitting or rot, or is this normal for the roots to dry and shrivel?

I have them in very porous soil, 4-5 inch pot, about 4 in. deep, south facing window that gets lots of sun. I have been
concerned they may be getting too warm. I also keep them behind the window screens to filter the sun a bit. In fact, I was adding more screening to filter even more sun, when I bumped them .
What should I do? I' m very new to Lithops. Thank you.

[1bigfruit]

Lithops get a lot of bright sun in the wild they are designed to take it. But they are not necessarily as heat tolerant as you might expect because they are generally buried with the tap root and plant body deep in the cool ground. Windowsils can be a bit hot and dry.
I grow a lot of mesembs and I generally try to keep them in bright light but with the pots away from too much heat.
Also I find that most mesembs prefer cooler conditions and hate porous pots. I dont have a single porous pot in my collection! I grow all of my lithops in 2:1 loam:sand in 10cm (4") pots which are maybe 5 - 5.5 inch deep so the tap root has some space.
In member topics I have lithops pictures in "greenhouse happenings".
Really good plants for south hot windowsils are pleiospilos nelii, P. compactus or p.bolusii. You can also grow schwantesia very well on windowsils.
Hope that helps D.

[Kamos]

Thanks for the great advice! That does help alot I'm giving them better ventalation
now, and more sun protection. I accidentally roasted an Argyroderma last week!

[iann]

Takes some to roast an Argyroderma! They are highly resistant to sunlight, very reflective, but perhaps high air temperatures would be a problem. I grow mine on the top shelf in the greenhouse where I know that almost any Lithops would be stone dead the first really sunny day.

Lithops roots are, for want of a better term, deciduous. They have a persistent "taproot", often a single root an inch or two long, but sometimes branched. This can become very thick on old plants. When the soil becomes wet they grow a quite extensive set of fine roots which will die when the soil is dry for any length of time. Although it is difficult to examine them directly, it is quite probable that they die anyway after a couple of weeks. It may well not be a coincidence that keeping Lithops in wet soil for longer than 1-2 weeks is very risky even if they haven't burst their skin by then. Equally, having the soil dry out in less than a few days is unhelpful because the fine feeder roots do not have time to grow. The thick persistent root seems able to take up some water, but not a great deal, perhaps just any dew that runs down the body.

[Kamos]

Thanks ian, thats interesting info. I'll have to rethink my soil mix.
I always appreciate your expert advice!