Lithops Help!

[bluestrudels]

Hi Folks,

Happy New Year! My name is Bernard, and I'm now to the cacti forum community.

I usually post at the Houzz/Gardenweb C&S forums and occasionally lurk around the forums here for added information, as the cacti community there isn't very huge.

I was largely encouraged by a few members to post my issue here, as they had mentioned a few senior mesembs growers (I think they mentioned Ian) can help me with my problem.

You can read more about my original post here
http://forums.gardenweb.com/discussions ... on-lithops" onclick="window.open(this.href);return false;

For a quick brief, I reposted some of the photos to show these "Fungal like" infestations on the leaves.
The 2nd plant sadly didn't make it, and now the neighboring plant seems to infected too and the growth is spreading.
What do you think I should do?

I've already split up all the plants into individual pots, it was a big mistake on my part to choose such a poor potting medium - styrafoam cup.
I initially thought it was a great idea since it was my only longer and narrow pot.

I stated with 4 in that pot, 1 died from drying up - so I compensated by water more.. then 1 died from this funal thingy, another is infected and spreading through the leaves, the last one is doing fine with new leaves growing out soon.

I know the fungral spread is largely due to overwatering, is there any way to save the last infected plant?

[kikithor]

I have been told by a few people to not water mine at all until spring. I just got mine tho so idk. Strange that one died from no water!

[bluestrudels]

Kikithor - I've grown a couple more lithops in terra cotta pots, and they do very well with my treatment of neglect. My trick is to only water them when I see wrinkles on the body. I provide an occasional mist to the pots so the roots can absorb moisture like how they extract water in the wild.

My soil are also very porous, it's equal parts turface, grit, perlite, growstones and 15-20% vermiculite.

I think the reason why the Styrofoam was such a bad potting medium is because it traps moisture and the long narrow structure makes the soil retain humidity much longer than I foreseen.

Now I'm just really concerned about this fungii thing... I might be losing another one to this disease, but at the same time I do not want to cause more stress to the plant by cutting the rot/scar away.

Bernard

[iann]

There is nothing inherently wrong with styrofoam pots, although obviously they aren't very robust. Rather than say they retain too much water, it is equally valid to say that terracotta dries out too fast. You have probably been lulled into a false sense of how much water is required, because the terracotta pot has been evaporating 90% of it for you. One good plan is to grow in one type of pot or the other, because managing watering in such different types of container is quite difficult.

Despite all that, wet soil in January isn't good. The first step should be to get your Lithops dry, by taking them out of the soil if necessary. The grey one in particular doesn't look good and I don't think you should get too attached to it. You could try cutting into it, even to the point of removing that whole leaf, but it is difficult to save them at this stage. Just make sure you leave the small new leaves inside intact. And don't be in any hurry to give them more water. Unless you live in a desert or the tropics the amount of water needed by a Lithops in the winter is approximately zero.

The colour of those Lithops doesn't look great to me. I suspect they haven't received anywhere near enough sun to toughen them up (and incidentally bring out vibrant bright colours), so they are just itching to rot at the first excuse. If the next one in line shows rapid changes then you'll have to act, but I've seen much worse damage to Lithops that they just shrugged off. Look at this one I froze last winter, it is just fine again this year:

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[bluestrudels]

Hi Ian, thanks for writing back.

You are spot on, I was lured to water too much when I saw the first signs of wrinkling. Then the mix stay wet for too long, eventually slowly poisoning the plants.

I tend to do better with terra cotta pots as I can guesstimate the moisture level by touching the pots.

I also spritz the pots to induce moisture during early mornings or late afternoons to keep the feeder roots moist without wetting them too much.

Here's a picture of them a month ago, now they look really good resting through the beginning winter here..





1) I had already removed them and potted into individual pots. They all are currently growing under lights. I know it's hard to provide sufficient light at this time of the year.

2) Sad to say, the grey one didn't make it.. it was already in a really bad state when I made the incision to cut away the rot..
It just dried up to crisp a few days later..


3) The next one in line doesn't look good, the rot/fungus seems to getting bigger and bigger by the day. I'm afraid if I cut it, it will die like the last one..
Do you think I should just leave it alone and let the plant combat the rot itself? I just want to do make the best decision to give the plants the best fighting chances.

I got these from Home Depot, and they were really cheap to begin with and I couldn't bear to leave them in the dark corners of the store with the store people watering it daily and sitting in moist peat moss.
When I repotted, one plant had already show signs of mild rot in the meristem.

[bluestrudels]

I also have a few more questions on watering seedlings, if you have experience in those too.

These guys are seed grown, about 3 months old now..
I started reducing water because they are splitting their old leaves and starting to show their first true leaves.
I always keep them in a humidity tray, water always refilled when dry - under lights and fan.
I recently reduced my frequency to 1.5 weeks.

And this happened.. Dried up seedlings..

I know seedlings are supposed to be kept moist for at least a year or two until they can be treated like adults.
Am I on the right track here?

It's only one pot that is more fussy than the others..









And here is the remaining survivor that is emerging a new set of leaves..

Note again: They have all been separated now..

[iann]

You don't need to keep the feeder roots alive on adult Lithops, so no need to keep spraying them. Unless perhaps you live in Arizona. Lithops, particularly the large ones most people grow, thrive when the feeder roots are allowed to completely die between water. Watering so often that this doesn't happen is a much better way to harm them Lithops feeder roots have a lifecycle of just a few weeks, then they seem to die even when give plenty of water. Persisting is a recipe for disaster, as with all succulents that don't have roots. Very light sprays can support plants in between times by allowing them to absorb a small amount of water through their main taproot, but this is only really necessary in a hot desert climate. I recommend you water your Lithops deeply and then leave them for at least a couple of weeks before doing it again. Leave them entirely dry over winter, either until the new leaves are through and the old ones gone, or until spring is well under way. And be prepared to let your Lithops shrink a bit in summer because they don't appreciate being force-fed when it is very hot and humid.

Seedlings don't need to be kept moist for years, only for a few months. Once the first true leaves start to appear then you definitely need to back off on the water. You could leave them entirely dry until the seed leaves die back, but I find it is best to give them intermittent water to keep them growing, but all the time letting the seed leaves dry up.

Only the one survivor from all those seedlings? They look pretty healthy in the photos. I'd guess over-watering rather than under-watering. Or maybe they got boiled in the sun? Anything that kills a Lithops, even a tiny seedling, in a short period of time isn't too little water. The roots on the dead ones are a little disappointing. Maybe your soil mix isn't suiting them. Perhaps too coarse? Or perhaps you are just wetting the surface and there is no incentive for them to grow longer roots? I like to start my seedlings under plastic with the soil slightly moist all the way through for the first month or so. Roots like this make for a resilient seedling:

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Here's what a full set of feeder roots looks like. Not many people see this because they are usually dead or lost when repotting:

meyeri-280910.jpg (64.07 KiB) Viewed 14836 times

This is what you should expect from the main taproot on a Lithops. It forms to more or less this length as a small seedling, then slowly gets thicker over the years:

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On a robust species like L. lesliei it can actually deserve the name "taproot". Look at that corky covering, it is good at absorbing small amounts of dew running down the leaves without having to grow any feeder roots.

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[bluestrudels]

Thanks for sharing the roots of your lithops Ian. I'll note in instilling a stricter watering schedule.

I noticed my plants are usually on the drier side.. Because they are mostly in clay pots and especially so when I have the heat on during the winter.

I apologize for the confusion. The last picture is the survivor from the all the plants that had rot/fungi which I had previously posted.

The seedlings were another separate question. I have a tray of 4 seedlings.. 2 Julii, 1 Hallii Geelkop and 1 Karasmontana, they all sit in the same humidity tray. I water whenever it's dry, it's only of late that I reduce my watering - that's when I encountered the smaller ones in the Karasmontana tray drying up. Maybe I should start separating them in individual trays on different watering schedule?

So far, they are all under lights, so I doubt my CPL is warm enough to burn them.

I know the roots seem a little sad, but I have no other way to inspect the other seedlings roots until I repot them. I'll take note to see if I can force the seedlings to dry up their seed leaves..

It seems the Karamontana are needing abit more water

[iann]

OK, thanks for the clarification. The seedlings look basically good, other than a few that seem to be drying up. It can be tricky caring for a range in the same tray, but not impossible. At the stage you show, they should be dry more often than not. And I mean completely dry from top to bottom of the pot. You can certainly water regularly, but should take care that you aren't leaving them constantly wet. You want those fat balls to gradually, or not so gradually, dry up and the nice new patterned leaves to come through strongly. Don't try to push them because that first set of leaves may be all you get until next year. If you're lucky you might get an extra pair during the summer. In the mix you describe, using a (very!) dilute fertiliser regularly will help.

The colour is quite strong. That's probably good, It is hard to give them too much light even at this size, especially in winter. If they are growing in direct sun, be careful that they don't overheat. Particularly behind glass with poor ventilation, they can boil to death in a few hours. They will rapidly turn white or transparent and they are dead, although rotting can cause very similar symptoms.

[bluestrudels]

Thanks Ian for all your great advise!! I'll pay more attention to reducing water..

Will send you more updates periodically!