The oedema says you're over-watering and it likes you might have something fungal going on, if not root rot, then powdery mildew. Also, over-watering is the most likely cause of the necrotic leaf tips and margins.

Do you wet the foliage when you water? If yes, not a good idea because plants with pubescent foliage are at generally greater risk of things fungal infections of foliage.

When leaf margins curl down, especially if leaves droop abnormally from the base of the leaf to the leaf tip, there is probably an issue affecting root function or health. The main causal suspects would be over-watering or soil compaction causing an inadequate supply of oxygen to roots, a root infection, or a TDS (fertility) level too high, which can limit water uptake.

Vermiculite breaks down quickly, and some plants have an allelopathic aversion to coconut products.

I would water less often. Use a wooden tell to "tell you what moisture levels are deep in the pot, at the bottom. Water when the soil is nearly dry or if you notice the onset of wilt. It's not particularly good to allow plants to wilt, but if you have to choose between a slight wilt as your trigger to water, it's better than over-watering. Remove and discard all diseased foliage and all dead matter on top of the soil, and it wouldn't hurt to hit them with an appropriate fungicide. Make sure there is good air movement in the room where they are kept. Plants with pubescent leaves enjoy a more perfect "boundary layer" of still air surrounding the leaves. As such, they tend to hold a thin layer of higher humidity air that will be higher in RH than the surrounding air. 40-50% RH should be plenty.

Are you fertilizing? You should be. I recommend highly, Foliage-Pro 9-3-6. It's a COMPLETE nutritional supplementation program in a single package and its NPK ratio favors plants. You'll go a long, long way before you find anything better.

More about using a "tell":

Using a 'tell'

Over-watering saps vitality and is one of the most common plant assassins, so learning to avoid it is worth the small effort. Plants make and store their own energy source – photosynthate - (sugar/glucose). Functioning roots need energy to drive their metabolic processes, and in order to get it, they use oxygen to burn (oxidize) their food. From this, we can see that terrestrial plants need plenty of air (oxygen) in the soil to drive root function. Many off-the-shelf soils hold too much water and not enough air to support the kind of root health most growers would like to see; and, a healthy root system is a prerequisite to a healthy plant.

Watering in small sips in order to avoid over-watering leads to a residual build-up of dissolved solids (salts) in the soil from tapwater and fertilizer solutions - which limits a plant's ability to absorb water – so watering in sips simply moves us to the other horn of a dilemma and creates another problem that requires resolution. Better, would be to simply adopt a soil that drains well enough to allow watering to beyond the saturation point, so we're flushing the soil of accumulating dissolved solids whenever we water; this, w/o the plant being forced to pay a tax in the form of reduced vitality, due to prolong periods of soil saturation. Sometimes, though, that's not a course we can immediately steer, which makes controlling how often we water a very important factor.

In many cases, we can judge whether or not a planting needs watering by hefting the pot. This is especially true if the pot is made from light material, like plastic, but doesn't work (as) well when the pot is made from heavier material, like clay, or when the size/weight of the pot precludes grabbing it with one hand to judge its weight and gauge the need for water.

Fingers stuck an inch or two into the soil work ok for shallow pots, but not for deep pots. Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone situation can wreak havoc with root health and cause the loss of a very notable measure of your plant's potential. Inexpensive watering meters don't even measure moisture levels, they measure electrical conductivity. Clean the tip and insert it into a cup of distilled water and witness the fact it reads 'DRY'.

One of the most reliable methods of checking a planting's need for water is using a 'tell'. You can use a bamboo skewer in a pinch, but a wooden dowel rod of about 5/16” (75-85mm) would work better. They usually come 48” (120cm) long and can usually be cut in half and serve as a pair. Sharpen all 4 ends in a pencil sharpener and slightly blunt the tip so it's about the diameter of the head on a straight pin. Push the wooden tell deep into the soil. Don't worry, it won't harm the root system. If the plant is quite root-bound, you might need to try several places until you find one where you can push it all the way to the pot's bottom. Leave it a few seconds, then withdraw it and inspect the tip for moisture. For most plantings, withhold water until the tell comes out dry or nearly so. If you see signs of wilting, adjust the interval between waterings so drought stress isn't a recurring issue.

Al

thank you so much for your sole answer. No one else replied. but never the less..

the brown/yellow dots on Eucodonia shall be normal someone said. Its a Eucodonia thing..don´t know better.

the leaves from kohleria had no yellow spots or grey spots. Or the yellow brownish part can be sun burn from water on the leaves. When I compare Google pics, its not spotwise, or bright grey and not uneven. Dark spots appear only holding at window.

I try to not wet the foliage, but leaves hide the stem, so I try to water the stem area also. Than leaves get wet sometimes. Small drops. I try to wipe them off when I see it.

soil compaction, why? I use perlite, leca, i tried also mixing orchid barks, gravel. Ok I can avoid coco and vermiculite next time, to try. My mother just used plain garden soil, and ther plants were healty, although soil got so compacted over time.

I have also read, 9 from 10 plants die from overwatering. Therefore I was very cautios. As then they did not stop become brown, I then took them off the soil, to inspect the roots. They were like hair, thin and dry, not moist or mushy. So I did not overwater? or did I and then they got mushy and then dried off because of lack from oxygen?

you write: "Water when the soil is nearly dry or if you notice the onset of wilt. " maybe of the plant species, I never saw them wilting or droppy. Stem was always firm. Sometimes one got sloppy leaves. I watered then, but it dit not help. Unfortunately signs of overwatering and less watering is the same!!!

about air flow. I open windows often for couple of minutes a day. It is very cold. How to get air flow? Its too cold to put them outside. Ventilator cools down more for the sake of air.

In winter I used a heater/radiator below the window sill. On the window sill there were my plants. My room is not bright, therfore I put them there so that get light. Maybe hot dry air also hit the leaves. I elonged, extended the window sill to avoid this, perhaps that did also not help.

40. 50 % humidity is ok? What about 60 or more? I use humidifier as they are exotic plants. But the mist is also cool. So hot and cold mixes together, is this good or bad?

I use fertilizer seldom, most of them are cuttings or very young. Maybe fertilizer would be too strong? I dilute it very. I try eggshell, banana or aloe vera so fertilizer dont oversalt the soil. I use rainwater or destilied water.

for short time ago I started to weigh the plastic pots. So I use always the same weight when its dry, or the same amount of water evey time.

You write: "Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone " 10 cm deep pots, cuttings or rhizomes are at the first 3 cm of the soil. The young roots maybe at half of the pot. Below that soil is wet though drainage holes exist. So if the water were to much, it would drop, but it did not drop. For my opinion the soil beneath, has no roots at the moment, so roots cant suck up the water, therefore last the final one-third of stays wet, but upper soil is dry. So what to do..Therefore I bought this humidity meter, everyone was very satisfied with it. They said its the solution to not overwater. When I push it into soil, it says dry. For me it is moist. This must be true, because the roots look also dry. So it is dry, I assume. Well this meter worked for so many people. Of course it says it will not work if you stick it into pure water. Its even written in the instruction paper.

I cant wait till the third end of the pot dries, than the middle zone of the pot, where the roots are(I assume), will dry out. Top soil anyhow.

I think I have to sacrifice some plants, to see where the problem is, overwater or underwater. I will definetly try the wooden tell method. I love them so much. I even wraped the pots in towels in winter, so they dont freeze on the window sill.thank you so much for your sole answer. No one else replied. but never the less..

the brown/yellow dots on Eucodonia shall be normal someone said. Its a Eucodonia thing..don´t know better.

the leaves from kohleria had no yellow spots or grey spots. When I compare Google pics, its not spotwise, or bright grey and not uneven. Dark spots appear only holding at window.

I try to not wet the foliage, but leaves hide the stem, so I try to water the stem area also. Than leaves get wet sometimes. Small drops. I try to wipe them off when I see it.

soil compaction, why? I use perlite, leca, i tried also mixing orchid barks, gravel. Ok I can avoid coco and vermiculite next time, to try. My mother just used plain garden soil, and ther plants were healty, although soil got so compacted over time.

I have also read, 9 from 10 plants die from overwatering. Therefore I was very cautios. As then they did not stop become brown, I then took them off the soil, to inspect the roots. They were like hair, thin and dry, not moist or mushy. So I did not overwater? or did I and then they got mushy and then dried off because of lack from oxygen?

you write: "Water when the soil is nearly dry or if you notice the onset of wilt. " maybe of the plant species, I never saw them wilting or droppy. Stem was always firm. Sometimes one got sloppy leaves. I watered then, but it dit not help. Unfortunately signs of overwatering and less watering is the same!!!

about air flow. I open windows often for couple of minutes a day. It is very cold. How to get air flow? Its too cold to put them outside. Ventilator cools down more for the sake of air.

In winter I used a heater/radiator below the window sill. On the window sill there were my plants. My room is not bright, therfore I put them there so that get light. Maybe hot dry air also hit the leaves. I elonged, extended the window sill to avoid this, perhaps that did also not help.

40. 50 % humidity is ok? What about 60 or more? I use humidifier as they are exotic plants. But the mist is also cool. So hot and cold mixes together, is this good or bad?

I use fertilizer seldom, most of them are cuttings or very young. Maybe fertilizer would be too strong? I dilute it very. I try eggshell, banana or aloe vera so fertilizer dont oversalt the soil. I use rainwater or destilied water.

for short time ago I started to weigh the plastic pots. So I use always the same weight when its dry, or the same amount of water evey time.

You write: "Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone " 10 cm deep pots, cuttings or rhizomes are at the first 3 cm of the soil. The young roots maybe at half of the pot. Below that soil is wet though drainage holes exist. So if the water were to much, it would drop, but it did not drop. For my opinion the soil beneath, has no roots at the moment, so roots cant suck up the water, therefore last the final one-third of stays wet, but upper soil is dry. So what to do..Therefore I bought this humidity meter, everyone was very satisfied with it. They said its the solution to not overwater. When I push it into soil, it says dry. For me it is moist. This must be true, because the roots look also dry. So it is dry, I assume. Well this meter worked for so many people. Of course it says it will not work if you stick it into pure water. Its even written in the instruction paper.

I cant wait till the third end of the pot dries, than the middle zone of the pot, where the roots are(I assume), will dry out. Top soil anyhow.

I think I have to sacrifice some plants, to see where the problem is, overwater or underwater. I will definetly try the wooden tell method. I love them so much. I even wraped the pots in towels in winter, so they dont freeze on the window sill.

look at the roots, what do you say? one is also from gardenia.

And this is from my Mother in normal basic garden soil. Then she went on vaccation, and I killed her plant also :((

Im sorry you are having so many problems. Perhaps you have been able to solve a few in the last month. Your watering issues might best be solved by wicking your plants as this should make the moisture evenly spread. Use a basic mix like Pro Mix, Black Gold AV, or plain Jiffy Mix seed starter cut with 60% or more coarse perlite. Mason twine or yarn works for a wick.

In nature Kohlerias tend to go dormant for a period. Although modern cultivars seem to keep on growing, they can get ratty looking with lower leaves looking bad although crowns look healthy. At this point, I usually cut off the crown, root it in a plastic bag till roots form and then pot as normal. Or I could reduce watering and then harvest the rhizomes for new plants.

Do know what is in your water. If you use city water beware of unfavorable elements. Check the PH level with a simple kit for aquarium water. And yes, do fertlize. Dyna Grow Foliage Pro was mentioned. I also alternate with Optimara 14 12 14 or Better Gro Orchid. All fertilizer is given constant feed at 1/8 tsp per gallon.

Lastly, dont give up! Sometimes it takes awhile to figure things.

Terri

are there drain holes in your beer cups?? take a razor blade.. and slice the bottom edge of the cup in 3 places.. so water can drain ..

if its cold outside.. dont open the window

propagate some new pieces.. and when those are thriving .... . get rid of the old ugly plants ...

ken

hi thank you. Meanwhile I had contact to a fungus, pests ogranisation. The llady told me it has to be pests, no fungus. I looked before. Then I used a very big magnifier and saw some https://youtu.be/9Rggx0a5g8M

these are beneficial but were sucking on my leaves. Can´t understand.