Need Opinion on whether to repot Oncidium Twinkle
 

I have not had Oncidiums before. I only acquired this plant on 3/4/16. I have watered and fertilized with 8-4-8 exactly once since then (this was all within the same watering). So I don't think I have had the chance to do anything to it yet except maybe put it in too much light (not sure). It's getting light from my balcony and I close the blinds partway when the light starts shining directly so the plant is not exposed to it. Temps vary from 68-72. The only other thing I can think of is that I used tap water, but I don't think it would have that effect after one go.

It is flowering, so I didn't really want to repot it until after it was done. But the yellow and brown part where the plant meets the media worries me. It looks like it might have root problems. I have seen something similar on a Dracula before and the roots were all rotted.

Should I wait or repot? It's possible this damage was already there and I just didn't notice it.

I would suggest, enjoy the flowers and wait until it has stopped blooming. The brown stuff was probably there before. Orchids don't do anything fast. If the roots are bad, when you repot, new growth will produce new roots. The somewhat shriveled p-bulbs suggest that they don't have a lot of roots (so the plant is running on reserves) If it came in that pot with the saucer, it probably did stay wet for too long - saucers are bad news, unless you drain the plant really, really well before putting it back in it. Spring, with new growth, is coming soon, so for now, relax and enjoy the flowers.

I will keep my eye on it then. Just to make sure it doesn't get any worse. This is not obvious in the pic, but the saucer detaches from the pot. So I'm hoping this means that it dries ok at least for now. I could try to stick a moisture meter in there and check...

Well, if I ever suspect fungus, I spray with an all out fungicide like Mancozeb.

Oncs do tend to die back a bit with the leaves, just keep an eye on it. I would hit it wth fungicide, because it has never caused me a problem but it has probably saved me from some problems.

A saucer to protect the countertop if the plant is well drained before putting in on one - just don't let any water sit in it. When I had to grow orchids in the house (the spare bedroom was my "greenhouse" I got plastic bins from a big-box store, and topped them with so-called "egg crate" light diffuser (a plastic grid with 1/4"/0.5 cm holes) that came from Home Depot. There was plenty of volume for the plants to drain into, and air circulation around them. Something to think about.

Take the saucer for the pot, and put another saucer that is a bit smaller upside down into the large saucer then sit the orchid on the upside down saucer. It protects surfaces and allows clean drainage.

Updates:
I think it is draining ok. In fact, I checked it out and it was too dry. :shock: Which is really unusual for me because of my tendency to overwater. I also noticed that it probably hadn't been watered enough in the past. So as soon as this is done flowering I'm switching it to something more water retentive. For now, I will just have to water it more often. This was also confirmed by dry leaves literary falling off upon contact.

I am still worried about the roots though, but for the opposite reason now. That they are dried out and dead.

Oncidiums get into a lot more trouble with not enough water rather than too much. This is in contrast to Phalaenopsis and Cattleya, which get into a lot more trouble with too much water.

I think large bark is only suitable for Oncidiums in high-humidity climates with owners who can water every day, if needed.

I have quite a few oncidiums and two twinkles. ES is correct about the watering. They like to be evenly moist but, not soggy. I water mine 2x a week depending on the temp and brightness. What I notice is the bark looks degraded and salty. If it were mine, I would take it to the sink and flush it well. Then feel the weight of it. When it starts to feel light, water again. I use medium bark, like you find in Better Grow mix. If you are a chronic underwaterer, chop up a little spag to go with it. Or, bil, I think, puts a couple of small balls of spag in the pot with the bark. I also use clay...It is hard to overwater clay and bark. Just my 2cents.

Yeah, I figure it acts as a moisture reserve while air can get in easily thru the pure fine bark.

I figure I'll just use the super tiny seramis and maybe some spag or synthic. Hopefully, roots are not too terrible. Flowers smell really nice! :)

Oncidiums can lose all their roots and come back well. The important thing is to put them in something like fine bark, and keep them wet enough.

Update:
I have tried flushing the plant as dollythehun suggested, but I think the media is too far gone.

The flowers drop off easily and the leaves continue to yellow and be lost. I have been keeping an eye on it and making sure the media doesn't dry out completely. I have also noticed that it was potted too deep in the pot which I'm sure is another part of the problem.

I think I will be forced to cut the flower spikes and repot or risk losing the plant. The media just may be too far gone and the ventilation may not be enough. There are holes on the bottom of the pot, but not as many as I am used to. I will probably make more, repot, and hope for the best.

Do you have any pictures of the HD plastic bins and egg crate set up? I'm curious how it worked out

Check out this photo on my website
http://orchidcentral.org/GrowingAreas/indoor.jpg

This is what I did back in the days when I lived in a condo and used the spare bedroom as my "greenhouse".

Startling Discovery
 

More updates:
So I took out all the media to find mostly charcoal and one microscopic piece of sprag. I found not one plant, but 2! One with 5 rotting pseudobulbs in the media!!!:shock: I have NEVER seen a case this bad, where it looks like someone literally shoved a plant under the media and didn't care. It's surprising because I got it from Hausermann's during their open house. The whole thing smelled awful! So I trimmed dead roots, which surprisingly there was not that many of, but I did lose quite a bit trimming off mushy parts. The plant on the right was in really good shape, but I'm not sure the plant on the left will make it. I closed all the wounds off with hydrogen peroxide and repotted in leca and seramis. Mostly because the roots are pretty delicate and I needed something more water retentive.

I'd strongly urge you against ever using hydrogen peroxide on orchids. It is very caustic to them, can eat the velamin right off of roots and cause damage to green tissue. You couldn't do much worse pouring drain cleaner (or hydrochloric acid if you prefer) on your orchids.

Seal cuts with a dab of cinnamon powder.

I do use cinnamon powder too. And hydrogen peroxide was extremely diluted. Probably about 80-90 percent water. But if it is that bad I will stop using it.

Is it still caustic at the stated dilution? I have used even less before. It's the regular 3 percent but super diluted. I usually only use it when there's a major problem. Such as a bunch of mushy pseudobulbs or lots of fungus on roots. Flower spikes and regular wear and tear are sealed with cinnamon. I rinse with water after using hydrogen peroxide, not the cinnamon.

Also wondering why it is caustic (not doubting it, as this is the case for people), when it breaks down into water upon contact with light? Is it just the reaction that makes it so?

At that low dilution it is probably not harming anything, but not doing much, if any, good either. If you want a fungicide in addition to cinnamon (which is quite good for sealing cuts) you could use Physan, which is not harmful to orchids at the dilution recommended on the bottle, and does a decent job.

Physan is what I use. Does a good job.

The peroxide that you buy is not going to eat great holes in your flesh, it's way too mild for that. It is an indiscriminate oxidiser, it donates an oxygen atom to anything oxidiseable and becomes water.
ie H2O2 > H2O + O- .
Point is, root tips are incredibly fragile, and no corrosive liquid, no matter how weak is going to do them any good.
H2O2 is very reactive, and almost anything will make it break down.

---------- Post added at 02:45 PM ---------- Previous post was at 02:42 PM ----------

An excellent fungicide is Mancozeb. At the first sign of potential trouble, a suspect plant gets bathed in the stuff.

Thanks everyone! I've been trying to learn more about orchids since 2015. This is the first time I have heard about not using hydrogen peroxide. I remember seeing Physan 20 at the local nursery and at Hausermanns.

I have not heard of Mancozeb before.

This might seem like a silly question, but is Physan 20 safe to go down a kitchen sink (I do some, but not all my watering there)? I also have cats, so I worry a little about using this. I suppose I could just put in spray bottle like I did with the hydrogen peroxide and use it over the potting tray only.

Is this toxic to people? I'm gonna to assume yes, but to what extent? Safe without gloves? Always use gloves? Shouldn't be in contact with food surfaces? Etc.?

Physan 20 is pretty safe for humans and other warm-blooded creatures once diluted, so I wouldn't worry about the cats. Probably not harmful on food surfaces, but just on general principles you'd probably want to clean it off. Remaining traces shouldn't be a problem. Small amounts of dilute Physan should also be no harm down the sink. (The concentrate would probably be an issue at the treatment plant, but not at the dilutions you would be using) About the only creature that I know it is quite toxic to is fish - don't use it in a fish pond or aquarium or anywhere near those! It attacks the mucus that protects the gills of fish and so can easily kill them. Spray bottle is a good way to dispense it anyway - you put it where you want it. So in general, the concentrate has some toxicity to humans, etc. but at the dilution that you use it, pretty benign if you don't have gills.

Even when I lived in St Louis, with humid summers, I didn't see much fungal trouble. I would suspect people would do better improving their growing conditions rather than running for fungicides unless they are growing in a really humid greenhouse.

I just don't believe somebody growing on a windowsill will get much fungus trouble if temperature, watering, air circulation and humidity are correct.

I agree about trying to keep your growing conditions tip top, but at the first sign or suspicion of fungus I hit it with mancozeb. Prompt treatment can save a plant, and if there is nothing wrong with it, Mancozeb won't harm it.