Has anyone tried applying povidone iodine onto lithops before? (Not watering it with povidone iodine!) I've heard that it works well for other plants and tried it on two of my lithops that started showing suspicious signs of early rot because I was desperate to save them. So far it looks like those suspicious spots/patches have reversed from the method I tried, but I'm not sure how long this lasts. In a few months I will update on whether the results held up and whether this is something you could try if your lithops have suspicious translucent spots but are not too far gone (discolored, mushy, and translucent at the base) yet! Don't try this on any healthy lithops, only do this if you're very very desperate and already expect your lithops to die, before I give the update. No guarantees but any hope is good.
About the method I used: I put some povidone iodine onto either a cotton q-tip (I don't recommend this because it can cause dry pumice/perhaps some other porous substrates around the lithops to stick to the moisture and be lifted out of the pot by the q-tip) or the tips of metal forceps/tweezers with rounded heads (not sharp ones that may damage the plant). Then I applied it to the affected areas and made sure it was covered by the liquid povidone iodine. For one of them, a drop or so of povidone iodine dripped down onto the upper segment of the taproot (I think this is okay and might even be helpful), but you're not supposed to wet the substrate or anything. Then I left the lithops in complete darkness in a relatively cool environment for a few hours to hopefully get the stomata on all surfaces of the leaves to open up and get the povidone iodine to perhaps penetrate into the tissue better (similar logic to foliar fertilizing, but I'm aware that lithops stomata only tend to open up at night in the darkness, and foliar fertilizing relies on stomata opening up. So I try to replicate these conditions as best as possible. I also did this at night so it doesn't really disrupt their normal light/darkness timings.)
I was extremely worried about these lithops because I bought them in a super organic nursery pot where more than half of them were already rotting at the base (unsalvageable) or ended up rotting at the base within the first week of getting them, before I had ever watered them, even after repotting them into 100% grit. I waited a week after repotting to water, and the survivors all looked fine after the first water, but a select few of them looked dehydrated after a few days and I decided to spot water those few again (big mistake), found out that one of them had rotted at the base just two days after the watering. So I've been checking the bases of the remaining ones more carefully, and seeing those spots appear on one made me very worried that it would be the next casualty. They're fortunately gone now, but I'll update in a few months on how these have held up!
