I don't know what it is or how to stop it, but I recently lost an aeonium to the same thing. it did not spread to any other plant, but over the course of a few weeks turned much of my pretty little aeonium black. I finally just cut it all apart and am trying to several healthy looking pieces, but no luck so far.

How fast is this spreading? Are these the only leaves that have been affected, and in what span of time has this happened?

I really don't know what that is. I could guess perhaps a fungal infection related to over-watering or soil that doesn't drain fast enough, but I really don't know. It doesn't look like a bad scale infestation to me, but I'd recommend you do a search on scale so you know what it looks like on an Aeonium (it {{gwi:613052}} that sort of become little bubble- or blister-like spots that stand up off the leaf). If it were scale, it would be spreading remarkably quickly.

It doesn't quite resemble sunburn to me, either. Sun coming through a window can burn leaves -- I've had it happen; we have old windows in our house and the sun really can beat in. But a sunburn wouldn't be spreading unless the plant is getting some direct sun every day and that is steadily burning more leaf area. And obviously, if it's in an all-day shaded location right now and the problem is still going, it's not an issue related to sun -- sunburn wouldn't be worsening in the shade.

With the plant sitting on a windowsill, were these affected leaves nearest the window?

The smaller rosette I can see looks very healthy, but I don't know what your soil mix is like. If the soil stays fairly moist all the time, it could very well be a fungal thing. I personally would spray with neem or something else (never spray/treat anything in direct sun -- it will burn the leaves) to be 100 percent sure you've murdered anything going on related to bugs and not a fungus, but I would venture to guess it's something that a change in soil or water could alter.

This post was edited by teatree on Mon, Aug 12, 13 at 21:31

I first noticed it last Friday (so 3-4 days ago), after having put the plants out for three afternoons on moderately sunny days. None of my other plants that were on the same windowsill seem to be affected so far, including sedums, crassulas, rhipsalis, echeveria, etc. They normally are kept on the inside of the same windowsill so it wasn't a terribly dramatic change in light exposure.

I should clarify that it first appears as pitting with no discoloration. The blackening/bruising shows up as a reaction to the pitting a few days later, which I've read is a very aeonium-like thing to do in reaction to any injury. I say that it's spreading because I am still seeing new pitting that hasn't yet turned black. The plant has been kept inside since I first discovered the pitting.

As with any succulent I also first worried about drainage because it had been potted in yard dirt, so I repotted it today in my normal succulent medium (50% potting mix, 50% washed coarse sand-- I know it's not optimal but my other succulents do just fine in it), and when I removed it from its pot I was pleased/surprised to see a well-developed root mass with no rot at all. So whatever it is, it appears to start and end with the leaves.

Right now it's under office fluorescents on a high shelf where the air circulation is better. I'm going to give it a few days there to rest from the repotting before I move it back to a different windowsill. To be honest the pitting pattern reminds me of something that killed off one of my sedums last winter, which makes me very nervous because I never figured out what that was, either. But that was under cold, wet conditions-- completely opposite from right now. I'm stumped!

Oh, duh, I was not paying attention to when you said you noticed the problem! I'm sorry about that.

As with any succulent I also first worried about drainage because it had been potted in yard dirt... That's the killer, right there. Some succulents are more sensitive to light than others, so some could sunburn in certain conditions before others might begin to do so, but the chances of sunburn happening while the plants are indoors is relatively low when it comes down to it. Your description of your soil (and, obviously, the soil/dirt it just was in) says that's the problem, and I might bet money you have a fungal issue. Especially if you know your soil wasn't/isn't ideal. When you have an unhappy plant, the very first thing you should think about is the soil (and watering). The second thing would probably be quality of light.

Some succulents, for a long while, will be more tolerant of less-than-great conditions than others. Just know, just because some other plants haven't had an issue so far doesn't mean the soil isn't poor. It also doesn't mean you won't run into issues with your other plants, that have been okay so far, in the future.

Just make sure the roots are healthy and white, not primarily brown and/or caked with soil. A plant can develop quite a root mass, but if the roots are mostly caked in soil, there are probably more dead and dying roots in there than healthy ones. Heavy, peat-filled soil sticks to roots and kills them, and sand actually helps retain moisture. You need a really high amount of pumice or perlite or something else to help things drain quickly, and no sand. Your mix now would be a huge improvement over yard dirt, yes, but it'd be sad to have continued problems or another problem with your new sandy mix.

If it's a fungal infection, it starts with the roots, not the leaves. Most of the problems out there start with the soil and the roots and your watering. Fungal infections, no question, are always related to a problem with the soil and/or over-watering. Until your soil mix is good, you can never be sure that you won't run into problems like this. Additionally, plants cannot grow under fluorescent/artificial lights, but need the real thing unless you have grow lights. I'd stick it back by a window, and if it were getting direct sun to which it hasn't been acclimated and you were afraid of sunburn, you could move it back a little distance to avoid the direct sun or draw a sheer curtain over the window during the direct-sun hours. But A. 'Kiwi' does like light sun, so no fearing sticking the plant outside -- all succulents and cacti are outdoor, not indoor, plants anyway, and that's where they really will thrive.

This post was edited by teatree on Tue, Aug 13, 13 at 0:29

Hi guys, just an update in case this information is useful to someone else later: As I mentioned, I repotted this plant, let it sit in a darker part of the office for a few days, and then returned it to its original windowsill. It's been two months and the dimpling and discoloration did NOT continue to spread past the initial few days. Eventually the affected leaves shriveled and fell off like normal, leaving the healthy rosettes. I now believe that this was an atypical sunburn.

Good to hear an update! Glad your plant is better. Someone will be able to make use of this info down the road. We all thank you for that!

Big Thanks to Colleen (teatree) for all her invaluable information! =)

This happens a lot to aeoniums especially when first brought home from the store. From my experience this is from to much sun. Are you planning on keeping this plant inside? Aeoniums usually don't make good houseplants. You should know aeoniums are summer dormant, but if this was mine I would still replant into a fast draining mix. I would also put outside. The best sun is morning sun and then shade in the afternoon.

Thank you so much! I was frantic lol I do know that it is dormant so I resisted the urge to water! I really appreciate it!!

I don't have a lot of experience with jades, but hopefully somebody can give you an answer ;)

I have that too, it's Aeonium Decorum. From my experience this succulent plant has the tendency to have black spots especially if the climate is hot and humid. Mine went thru that scarring symptoms accompanied by black spots. Then I learned that it desires moisture more than other succulents. But generally, watering them is like any other succulents, only water the medium when it dries out. The next thing I tried was to spray mist lightly the leaves every other morning and it did the trick. After a week or so the scarring and spots begin to lighten and disappear. Nevertheless care must be taken not to over spray the leaves as the access water will go down the medium which may make the medium wet and cause root rot. The best is to place it in bright but non-direct sunlight spots, to avoid sunburn. Enjoy planting Aeoium D.