What's wrong with my E. micromeris???

[Steve Johnson]

Mr. "Hey, I'm an Epithelantha Expert" is feeling about as tall as his micromeris at the moment...

After going through some worry about establishing mine over last year's growing season, I was so pleased to see how good it looked in Spring. Here's the micromeris at the height of its flowering and plumpness in early May:



Then it started to shrivel again. I won't bore y'all with the details on watering frequency, but I'll just say that I haven't been over-watering. However, I was back to being concerned when the micromeris wasn't storing up water again. Maybe just concentrating on more root growth? The neck retreats under the surface between waterings, so when the neck appears after the plant gets watered, it's a promising sign that the roots are still working. Now here's the micromeris as of today:



Last watering was Saturday night, and we see the top of the neck popping up again (green arrow). Not bad, but what distresses me was a new development I detected yesterday evening -- not good at all. The red circles indicate what appear to be a band of shriveled tubercles. FYI that's the plant's northern exposure, but not the worst of it. Here's the worst:



The micromeris is tilting toward the sun, and the southern exposure looks like a badly deflated tire. This may have nothing to do with the tubercle damage, but I'll bring it up just in case. I try to be observant about picking up on small sudden changes, but I'm always kinda depressed when they get the drop on me. (I can tell you all about that when a few of my cacti got hit by flat mites for the first time.) After so much time with no hint of trouble on the skin, I have no idea how long the tubercle damage has been going on. The really dense spines on micromeris certainly don't help. Here are the possibilities I'm coming up with -- let's discuss and maybe we can figure out what happened:

1. Mites? No sign of red spider mites or their webs, so I highly doubt that. My run-in with flat mites makes me wonder if this is what happened. The counter-argument would be that they go after the base and work their way up. Can't see it happening, although perhaps flat mites ignore the rule and do whatever they freakin' want. I started spraying the micromeris with IPA, so it'll get the regular treatment every 2 weeks unless and until someone is able to tell me this wasn't a flat mite attack.

2. Root mealies? My existing collection has been mealy-free since I started building it 2 years ago. A bunch of new plants came in recently, but they came bare-root from highly trusted sellers, so root mealies are pests I would suspect the least right now.

3. Sunburn? The micromeris enjoyed the full sun under my 40% shade cloth enclosure last Summer. No hint of sunburn then. The plant is well-acclimated to my area, and the Summer so far isn't even close to the heat and sun I went through last August and September. Seems awfully strange if it's getting sunburn now, but I won't rule this out.

I have no patience with self-delusion, so I already accept the fact that there won't be any healing of the damaged skin. All I'm concerned about moving forward is to find out what happened and keep the damage from getting worse. I'd really appreciate whatever thoughts any of you care to offer.

Thanks!

[keith]

Thats is what just happened to one of my Astrophytum asterias and 2 of my mammillaria dehertiana all many year sold from seed. If it was easy it would be a boring hobby. Now you will have room for another one.

You need to try again, minimum organic in the soil. Check the roots when you throw it out. probably fungus infection ? cross section the plant I bet it has orange color in the vascular bundles.

Throw all the soil away and try again.

[CactusFanDan]

Don't give up on plants so easily Keith. It doesn't look serious to me and owing to Steve's treatment I doubt that it's going to be due to rot. It could just be corking after all, but you might wish to follow a preventative course of miticide. If you're daring you could pick off an aerole from the offending area to try and get a close look at the actual body of the plant. Get up nice and close with a magnifying glass to see if there's anything there.

[iann]

Doesn't look like sunburn.

Does look like mite damage, but they could be long gone by the time the damage is like this. Forget spider mites and their webs. I'm half convinced that nobody even has these on their (globular) cacti, certainly I've never seen a single one on mine despite them being all over some other succulents. False spider mites don't make webs. Could also be unconnected, but not many things make a nice even band of scarring round the plant.

Leaning over into the sun is normal enough as the plant starts to deflate. Often they will straighten when it really drops down into the soil. Overall it doesn't look great at the moment. I don't like that green appearance on the lower part of the plant. I'd be getting out my lens and having a close look, which is easier when they plant is fat

[Steve Johnson]

Okay, I sounded the first flat mite alarm when I finally saw suspicious damage around the base of my Mammillaria deherdtiana a month ago. I got out my 10X magnifier, and seeing those incredibly tiny little nasties on the tubercles confirmed the cause. I gave my micromeris the same close-up inspection around that time, although I think it would've been pretty much impossible to spot the mites hiding under the dense spines. And I'm not sure if it would've made any difference with a fully plumped-up plant either. However, I can sure see the shriveled turbercles under the magnifier now. The damage looks an awful lot like the aftermath of what happened to the deherdtiana, so I'll have to chalk this up as a flat mite attack.

If the micromeris didn't look so thirsty after all this time with regular watering, maybe I could've checked the flat mite damage early enough with IPA. Then again, maybe a healthier plant wouldn't have been attacked to begin with. I've given this thing over a year, and I'm to the point where I just feel like digging it up to see what the roots look like. Is there a good reason for doing this, or would I be disrupting the plant at a time when it's basically healthy enough to keep growing? If anyone has a response, I'm all ears.

By the way, Keith -- I grow my cacti with mineral mix, so fungal rot is extremely unlikely.

[iann]

You should be able to lift it out of the pot without disturbing the roots much. Or is that a downside of your soil mix? In my soil, if the roots are healthy then no way the rootball will fall apart. If it does then the roots are no good, perhaps just because they don't fill the pot but that in itself is a problem.

[Steve Johnson]

You should be able to lift it out of the pot without disturbing the roots much. Or is that a downside of your soil mix?

Nope, should be totally doable, so I'll give it a shot on Saturday. What comes out of the pot will settle any questions about the condition of the root ball, and I'll come back with a report to get an assessment of what's going on. Worst-case scenario? The micromeris may not be worth trying to save, and I'll get another one next Spring. They're easy enough to find from CoronaCactus.

I'll give you an update on what I find out Saturday. Thanks, Ian!

[keith]

By the way, Keith -- I grow my cacti with mineral mix, so fungal rot is extremely unlikely.'

I disagree with that epi's rot off easy.

looks like orange rot to me. If you grab the top and wiggle it is it very loose ? Most cactus have a firm feel to them unless you just watered them.

Root rot and they get very loose feeling and don't firm up. Like the tissue has turned to mush. I don't like that color.

Could be a old spider mite infection. epis do get spider mite.

Anyway if its really loose in the pot I would take it out of it's pot and see what's going on. If it's nothing you can repot in a week or so. Firm in the pot then maybe just leave it alone see what happens,

[iann]

Epis rot easily? What are you doing to them? I've grown hundreds from seed, still have perhaps 20, and I've never had a single Epithelantha rot.

I watered my Epithelanthas a couple of days ago and they fattened up nicely. I don't live in Arizona (or perhaps more accurately Texas or Mexico), but my greenhouse the last couple of weeks is perhaps more brutal than outdoors in LA.

Here is a nice SB 1327 from seed. It flowers noticeably earlier than other forms. No problem seeing what is happening under the spines on this one.

micromeris-0717.jpg (73.79 KiB) Viewed 2589 times

Even recently repotted E. bokei are showing a little skin where it was entirely white just a few days ago.

bokei-0717.jpg (44.01 KiB) Viewed 2589 times

[Steve Johnson]

After going through this song and dance for 14 months, I decided a few days either way to settle the matter wouldn't make any difference. So that's what I was up to yesterday evening...

When I unpotted the micromeris, here's what I found:

1. The roots are still there, but no more of them than I saw when I unpotted the plant a year ago. So much for the idea that at least I'd see the roots fill in more.

2. Good news -- no rot, so Keith can forget about that possibility.

3. 4 days after the plant's last watering, the pumice/DG mix was still moist after I took off the top dressing and exposed the neck. If the roots had been working properly, the mix would've been mostly dry -- no mystery there with regards to point #1.

4. After the roots made a valiant effort to grow through March and April, the volume of mineral mix in a 3" tall pot was just too much for them. I'm sure that upping the watering frequency after early May didn't help either. Put these factors together, and an ailing micromeris invited the flat mites in for a go -- no mystery there either.

Although I'm growing all my cacti with waterproofed terracotta, I was smart enough to keep the plastic pots I was experimenting with last year. Here's the micromeris on its 3rd repot:



The dimensions on this plastic pot are 3" diameter x 2.75" depth. However, the pot has a .75" lip which allowed me to finesse the situation, so the actual growing volume is 2.5" x 2". Guess I learned the hard way that Epithelanthas have little tolerance for over-potting, so I hope that under-potting will be enough to get those roots going again. And I'll have to be very cautious about watering frequency -- I've been there before.

Assuming that I can save the micromeris, I'll still be stuck with a badly scarred plant. Although I dislike the idea of giving it away just for that, I would've been tempted with the very limited amount of free space I had on my old plant bench. But the new bench gives me more space that hasn't been filled up yet, so why not have 2? I'd like to see how this little guy does first, then it'll be time to get a new micromeris from CoronaCactus next Spring.

[iann]

We all know what rule #1 is, and rule #2 is always remember rule #1, but rule #3 should probably be don't overpot. My largest Epithelantha, and it is bigger than yours, is in a full height 2.5" pot and I consider it slightly overpotted. The roots came close to filling it when they went in and I'm sure they do now since E. micromeris generates lots of roots in my soil mix. The ones I posted in this thread are in 2" square or 2" round pots. The roots on the E. bokei certainly don't fill the pot all the way to the bottom but I don't have smaller pots. No problems so far and hopefully the tiny pots won't stay wet too long.

Four days isn't so long for soil to stay moist, but if there are no roots in the moist soil then you're gambling that it will dry out some other way before the plant rots. Hard to water a plant generously in that situation.

[oldcat61]

What about trying a plain clay pot if you're so worried about damp soil? I know all the reasons not to use clay but it works for me. Sue

[Steve Johnson]

What about trying a plain clay pot if you're so worried about damp soil? I know all the reasons not to use clay but it works for me. Sue

Don't mean to be snarky, but what you suggest is not a good strategy. If plain terracotta works for you, then more power to you. If it were me and I knew then what I know now, I would've transplanted the micromeris in a 2.5" waterproofed terracotta pot as soon as I got it. Going with the smaller plastic pot I'm using is a much better strategy. Yeah, I still don't like plastic, although if the plant bounces back, I'll let the roots grow in as much and as long as they want. Then I'll have to decide whether or not the micromeris is ready for a 3" pot. Maybe in a couple of years, although I honestly can't see the rationale for unpotting the plant yet again to look at the state of the root system before then.

Ian, my heartfelt thanks for the time you're taking on all this. If the adjustments show up in a better outcome, I'll be sure to post up some before-and-after photos in a new thread documenting the save. As for the rest of you -- I hope this little experience is something you'll be able to benefit from.

[oldcat61]

Oh you're not snarky Steve. We'll agree to disagree & my micromeris sends get well kisses to yours. Sue

[iann]

Maybe you're flailing with this plant. Despite the sort of glib advice seen all over the internet, a cactus doesn't re-establish a week after you transplant it. Especially if you rip half the roots off, or if it just didn't have many roots to start with. They take many weeks, even months to properly re-establish. Maybe this one was just starting to do OK, then it got hit by mites, and now it will need a bit more time again after being dug up.

Or maybe not. I would have put Epithelanthas in the transplant-and-water-a-week later category, rather than the Ariocarpus transplant-and-forget-for-a-month category, but those are plants that already have great roots going into the exact same soil mix.