other one

This is an epidemic!
If that isn't mites, then it could be temperature extremes or lack of water has damaged the roots or over-fertilization. It doesn't look like a Ph problem with acidified soil

I would put that plant in an isolation dome, water carefully and wait to see if it corrects itself. That crown may be gone but the plant may sucker another crown. Not the most elegant solution but it will save something. If you have leaves put down or other healthy plants, you might consider tossing that one.

One mistake I made with sick plants was to repot drastically, sometimes more than once in a week; medicate with sprays, drenches and powders; move from one spot to another and generally play plant doctor.

Now I correct whatever I believe caused the problem, in this case under-watering, put the plant in a dome and wait to see if that corrects the problem

If not then go to the Plant Doc Manual over at Optimara or search the threads for another solution.

Hope this helps. These crown problems may be seasonal.

You said they were under potted, often dry and the drainage holes weren't great either. So, correct those issues and see what happens....
The second plant has a tight crown, which could be either too much light or too much fertilizer.
As lucky said, too cold can be a problem too (especially if you start watering more frequently).
Fix one thing at a time, give it a few weeks to see change, then look at the next thing.
Just keep in mind that your plants aren't doing badly, just not thriving. So no need to change EVERYTHING completely. Just adjust.

Karin

The second one was getting too much light previously. A few weeks ago maybe. After moving it, the problem started to correct itself. The leaves in the center have grown out and are bigger than before. But then the yellow center showed itself.

I will back off on the fertilizer. I dont use a lot, but they are potted in miracle gro so the combination could be too much, since they are babies.

I do have a few of this variety. One that is very beautiful. But apart from that one plant, it's not my favorite. (It is interesting how light levels effect the appearance of a plant. This variety looks the best reaching for light.) So I wouldn't mind tossing it if something were at odds with its recovery.

I havent brought any new plants into the house in at least a few months. But anyone think it looks like mites? I wont even mess with it if it does.

In general, on this Forum, some of the experts have noted
that they don't like MG. (I use it as it is convenient.) But
you might want to do a search to read what the experts
had to say. It was in the past, on older threads. I think MG
has a chemical in it that long-term is not good. There were
differing opinins. It might have been the Nitrogen. J

What is the alternative? I use MG because it is cheap and readily accessible. Any alternative would need to be both.

Mites can be spotted with a loupe or any high power magnifier depending on your eyes.

Mites distort as well as grey and stunt the crown.

There are pictures on the web of mites on schefflera which show clearly the kind of distortion, wilting and withering of plants. Google Mites Schefflera.

I had broad mites. I brought them in on some begonias. The mites spread to the geraniums, the diffenbachia and the schefflera then to the violets.

Mites look like a combination of cultural problems, distorted new growth (crowns) yellowing leaves.
Mites resemble a blight and the damage is done quickly.

My geraniums were fine then suddenly looked dry and withered. Looked like they had been hit with a blow torch.
I thought it was cultural so I kept watering, fertilizing, repotted...

Then I got a loupe...

I doubt it is mites but it is worth the price of a loupe just for your own peace of mind

Ew lucky, that sounds similar to spider mites. Those are easily taken care of, at least, with soapy water. I spray my palm with neem oil insecticidal soap periodically as preventative against spider mites. I dont suppose that would work for cyclamen mites?

There might be some ideas on the other threads going on now on a similar topic. MG is considered expensive. However, for a small collection with a few plants, it is convenient.

I have very similar looking plants and I have been using MG 50?50 with perlite, but I have also been fertilizing. I started with 1/4 per gal and went down to 1/8 per gal. I got a loupe and I see nothing moving on my plants.

Dixie

Lauraeli
I used Sprectricide Lawn spray diluted on the Schefflera. I cut it back to the ground finally. Removed all leaves and sprayed the soil. I drenched the soil with tobacco tea.
I removed all foliage from the geraniums, sprayed the stalks and drenched the soil.
I lost the diffenbachia and AV's.
There are miticides but I hesitate to buy on the internet because I could be getting plain water for a fancy price. Those miticides are in quantity and very expensive from the real deal manufacturers.
I have heard that putting a hotshot pest strip in a plastic bag with the plant, tie the bag shut and leaves for 24 hours. Repeat in 3 days works but those pest strips are for empty cabins or parked recreational vehicles, not recommended for inhabited areas.
The Rope Growers Association has plenty of threads about how to get rid of mites. I guess mites are a huge problem in cannabis crops in Southern California.
I had to basically cut plants to the ground and regrow to get rid of the problem, not a good solution for AV's.

Weighing in on mites: Lauraeli, I don't know if your top plant has mites or not, but anytime I find a crown that doesn't look just right, I pull the plant & place it elsewhere. I do have a scope but finding the little buggers can be tricky as they hide from the light. Watch the plants that sat next to your suspicious one. If the same crowns show, you may have the beasties. Again, I would confirm before treatment. Some people toss their plants. I fought broad mites for a long time with different remedies. Then I bought some Forbid and that eliminated them in one treatment.

On MG, a number of accomplished growers use MG potting soil mixed with perlite. I too have used it; it may not be my favorite but it works. The amount of fertilizer in the MG perlite is negligible so I am not overly concerned about that. I don't like their perlite because it is so small and dusty; I try to find Schultz brand as it seems to be of a higher quality.

Terri

Here are two old threads that might help : AV dying a slow death ... And
Am I on the right track?
Both of these have tips.
Terri, your procedures are good advice. Any plants that look " off " should be separated . If the problem turns out to be MG, then there is no point in tossing a plant until you resolve the issue. WhiteLacey had numerous advice, most of what I know I learned from reading old posts and experimenting with the advice given here. Such as switching brands if fertilizer, repotting to freshen the soil, not using vermiculite, you can get a more pure form of peat and reindeer or sphagnum Moss. But if a person has less than a dozen plants , they might not want to bother. Optimara fertilizer is supposed to be better than store bought brands. As for soil, in the spring, consider ordering something new. Again , the experts and those with large collections do not seem to recommend MG over the long term. Seems that if there are three threads with the same problem using MG, then that is an obvious fix. J