Dendrobium Leaves Turning Yellow & Falling Off

[King_of_orchid_growing:)]

The black splotches are mold.

The leaf is completely dead and beginning to decompose.

The mold is not the reason why the orchid is dying.

It's most likely dying because it was being grown in a pot full of densely packed moss.

Dendrobiums don't usually grow on moss covered trees. Very rarely do some species do so. Most of the times, epiphytic Dendrobiums are found on trees with lichen growing on them.

Moss has excellent water retention properties. It is also very acidic. Improper moisture balance and improper pH can cause problems.

Like I had mentioned, too much moisture is equivalent to drowning the roots. The dense moss in the pot, is suffocating them because there is inadequate gas exchange.

pH is rather complicated, and I don't quite know how to explain how it factors into the equation. But trust me, it does matter to some degree. It's not necessary to obsess over pH values, however - (that's a good thing!).

[Becca]

I have Dendrobium Samurai, Dendrobium Glorious Rainbow, Dendrobium Mingle's Sapphire all potted in just sphagnum moss and they love it! I just make sure they dry out in between waterings and not stay wet for to long. They have been in moss for at least a year and I haven't had any problems with them. My humidity is around 60 to 70% in my orchid room.

[scy]

Hi! I just wanted to give an update on my dendrobium. I followed Philip's advice and cut the stem back, peeled back the moldy leaves and waited a few days to see if the last 2 leaves were changing color. The last 2 leaves remained green for quite some time, so I felt comfort in knowing that I stalled its death. I continued the alcohol swab and think I've removed all the scale as I haven't seen anymore in the last 2 treatments.

One of the leaves is very slowly starting to turn yellow so I wanted to look at the roots and see how poorly they were. I did look up what healthy roots look like and I don't remember it looking thick and plump. Although it probably caused more stress, I would rather look and see what else I could do rather than sit back and watch it lose its 2nd to last leaf.

I ordered root hormone. When it arrived, I unpotted it, examined the roots. They were kind of thin but when I felt it, most of what was left was firm and not mushy. I trimmed off the mushy parts with sterilized instruments. I noticed that there was one green root while the others were white. I soaked the roots and bark in the root hormone solution for about an hour and quickly dipped the roots in physan solution. After seeing the green root and feeling that the white roots were somewhat thicker than before, I began to have hope. I almost repotted in the same pot but then I remembered that you said that the pot was too big. I didn't have one small enough for it, so I scrounged through my leftover take out containers and fortunately found 1 pint size container. I made my own drainage holes with a screw, pliers and a candle. I tested it to make sure there would be no standing water before repotting it. In the meantime, I've moved it to a warmest room in the house in hopes that it will encourage root growth. It's sitting by an east facing window with the shades drawn so it will get indirect sunlight and the temperature is about 75 degrees. I'll keep a watchful eye on it to see if there is improvement.

[Becca]

You did great with the container/pot you made! I have a ton of those same containers that I use for watering and other orchid related stuff.

I also wanted to say that if your dendrobium does loose all of it's leaves, it isn't the end of it! I have had dendrobium loose all leaves and still bounce back!

Also most dendrobium roots are pretty thin and wirey looking, I would never describe them as thick plump. Maybe a phal or a cattleya would have plump roots, but not dendrobiums. Don't loose hope, it sounds like your on the road to recovery!

[scy]

Thanks! Wow! The leaves fell off and it still bounced back? That's amazing! Every morning when I went to refill the water in the humidity tray, I just kept looking at my orchid thinking, "PLEASE DON'T DIE!!!" I did decide to cheer myself up beforehand and bought some baby phals so I would at least have some cute little ones to cheer me up while worrying about the other one.

It arrived with fresh sphagnum moss (as a lot of it is green) and I want to avoid the same mistake as my dendrobium. I would like to start semi-hydroponics after reading what others have posted in that section. I will follow up with a post there regarding that. How can I make sure that I do not overwater these phals in the sphagnum moss? I've been afraid to water it since it arrived, so I have been using a spray bottle to carefully spray the moss and avoiding the leaves and crown at all costs. I just spray until the moss is damp and not drenched.

[Becca]

They look nice an healthy! Moss can be very difficult to grow in. I've rotted my fare share of phal roots in it. My advice, or what works for me is this. I grow in clear pots (sometimes slotted on the side) so that I can see the phal roots in the moss. They will be green when moist and silver or white when dry. When I see the roots are dry I know it is time to water. My other method is that I wait for the moss to dry and feel crunchy. I have read that phals aren't supposed to completely dry out, but they don't stay dry for more then a day or so. Also how tightly packed the moss is will depend on how quickly it dries out. The tighter packed, the longer it will take to dry, the looser the quicker it will dry. I also use sytrofoam packing peanuts at the very bottom of the pot and sometimes directly under the phal so that the center will not stay moist longer then the outer part of the pot. This is what works for me, perhaps it might help you. You will just have to find what works for your growing conditions. Keep up the good work!

[Becca]

Forgot to ask earlier if your dendrobium has any new eye's or leads that look like they might be getting ready to do something? If have a couple dendrobiums with active eyes and leads, these new leads will eventually grow and put out new roots which will help to save your plant. If not, and you do happen to loose all leaves, as long as the stalks don't turn yellow or brown and stay plump it should hold through until spring when most of the new growth happens. I'm not trying to get your hopes up to high, this is just my experience. But I have also had several that had canes turn yellow and go mushy and die on me.

[scy]

Thanks for the advice on how I can get better success with moss! I have to admit that I'm afraid of using moss but since many places sell their orchids in moss, I figure it's important for me to learn how to work with it rather than avoid it all together.

What do you mean by "new eyes?" I repotted 4 days ago so I don't see any progress yet. The canes are looking a bit more shrivelled than before. I checked my skewer and it's just slightly damp so I'm going to water it again. It's potted in bark so drainage and air flow in the roots is good. The water immediately just flows out of the pot, so I'm going to try soaking the pot in water for 10 minutes instead to see if I get better results.

One of the smaller canes fell of during the repotting. It had no viable roots. I'm pretty sure that there's no hope in saving that one, since it has no leaf or roots - just small bit of cane. I'm using it to practice sphag and bag to see if anything will come of it.

[quiltergal]

A couple of things to point out that haven't been mentioned yet.

1. don't put cinnamon on roots. It's fine to use on green parts of the plant like leaves and spikes. It's far too caustic for root tissue and will damange the velamin.

2. Dendrobiums do not grow new roots from old canes. What you should be watching and hoping for is the beginning of a new cane to emerge. The new cane will grow it's own set of roots. Even if the old canes drop all their leaves as long as you have a new growth started I think your plant will survive. Leave the leafless canes intact. The plant will use them as a reservoir until it has grown a sufficient root system to support the plant.

3. I'd also recommend growing it warm. This type of Den does not require any cooling to grow and bloom successfully.

Is the small bit of cane that fell off still green? If it is lay in horizontally in a bed of damp sphag and put it in an open ziplock bag. The cane will try and grow Keikis from each leaf node.

I have brought a similar Phal type Den back from the brink. You just have to be patient.

[scy]

Thanks for the helpful tips! The cane that accidentally fell off was a new one, because it branched off the big one that had flowers. It was the smallest one of the group. It has no leaves as the first leaves to turn yellow and fall off came from this one before it broke off.

The cane is still green. I have it sitting in a ziplock on top of a damp, folded paper towel (as I didn't have any sphag when I did this). I soaked it in rooting hormone solution and quickly dipped in physan before putting it in. I air it out a few minutes every morning when I look at it to make sure there is no mold.