Dendrobium leaf yellowing - Orchid Board

farley101 · #1 01-12-2020, 07:36 PM

Hey all,

Looking for a little help with this Den Somrak Candy I got a few months ago. I have attached a picture and it isn't the greatest representation of the color but all the leaves are fading to yellow. I have had it in my living room where the temps are between 60-65F with low-ish humidity in the mid-30's. I recently moved it to my growing shelf that has LED lights, 60+% humidity and pretty consistent temps around 70. Not sure if the move to the new environment shocked it or what. I figured it would do better in the heat and humidity

Any ideas appreciated!

Roberta · #2 01-12-2020, 07:45 PM

If you moved it to much brighter light, you can get that yellowing in response (generally, best to increase light gradually if you can) Any sudden change can be a shock. I hope that you have increased the watering to compensate for the brighter light and higher temperature. I can't look up its parentage to learn more about the conditions that it really wants, since the hybrid appears to be unregistered. It does look like one of the warmer-growing Dens. In the long run, it may still do quire well there, but perhaps you can move it away from those lights a bit to give it a chance to adapt.

farley101 · #3 01-12-2020, 08:03 PM

I just made a shelf in the growhouse I have a "dark" one since I have a rescue phal that seems to be not liking the light either, new leaf turned purple. I'll move the den down there for a bit to get a break from the bright lights. Thanks for the quick reply Roberta!

farley101 · #4 01-14-2020, 03:32 PM

So an update, one of the pseudobulbs appears to be rotting from the top down. Seems this is a bigger issue than it originally looked. Should the top be trimmed back to try to keep the rot from spreading? The rest of the plant isn't looking that great, not sure if waiting is the best option. Attached pic of rot on the left cane. Thanks!

Roberta · #5 01-14-2020, 03:41 PM

You can peel off those two leaves (which are on their way out anyway) which will give you a better idea of what is going on with the cane itself. If you see rot, then surgery is in order (I recommend single-use single edge razor blades, very inexpensive in the paint department of home improvement stores... they are sharp, and being single use you don't risk spreading problems to other things) If the cane itself isn't showing rot, then leave it alone - many Dens bloom on leafless canes so if there isn't a rot problem you would not want to cut it)

Also... you said that you recently got it. Did you repot at that time? The medium in the photos looks good, but if you didn't put it there, a vendor could have put fresh bark on top of whatever was there for appearance. So if you didn't recently repot it, a look at the roots would be a good idea. If the roots are bad, a repot with fresh bark, and then watering only lightly, will give new growth in the spring a good start. If you repot, make sure the plant is held firmly in place... if few roots, then a stake helps. New growth brings new roots, the plant can run on the reserves stored in those canes for quite awhile.

farley101 · #6 01-14-2020, 04:44 PM

Hey Roberta,

I will get rid of the leaves and see what it looks like underneath. The vendor claimed that it was freshly repotted before I got it. I'll do a quick exploration and see if anything looks bad but I don't expect that to be an issue. Thanks again!

---------- Post added at 02:44 PM ---------- Previous post was at 01:53 PM ----------

I guess I should have expected this.

There was a green foam plug down in the mix, which I suspect is keeping things very wet around the roots. There didn't appear to be very many roots and the ones there were pretty squishy. Also, the leaves at the top of the cane just popped off and the cane looked to be starting to rot at the top. Cleaned it all up and will be repotting shortly. Whew!

Quote:

Originally Posted by farley101

Hey Roberta,

I will get rid of the leaves and see what it looks like underneath. The vendor claimed that it was freshly repotted before I got it. I'll do a quick exploration and see if anything looks bad but I don't expect that to be an issue. Thanks again!

Roberta · #7 01-14-2020, 05:31 PM

Maybe the vendor "just repotted it" but it should have been done 6 months ago... Good catch! With TLC and a little luck, hope for some new growth as the days get longer.

SouthPark · #8 01-14-2020, 05:50 PM

Quote:

Originally Posted by farley101

There was a green foam plug down in the mix, which I suspect is keeping things very wet around the roots.

That's very likely what did all this. The person that put it there most likely have their own watering plan, where they know just how much water to apply when they do water.

They probably shouldn't have put that foam plug into there in the first place - in my opinion. They can do it for themselves to grow, but shouldn't do that when they send the plant away to somebody.

Maybe a spray of thiomyl on the whole plant prior to repot could be beneficial too - just in case.

farley101 · #9 01-15-2020, 12:16 AM

Quote:

Originally Posted by Roberta

Maybe the vendor "just repotted it" but it should have been done 6 months ago... Good catch! With TLC and a little luck, hope for some new growth as the days get longer.

Yep, will keep it a bit drier for now and hopefully there will be some improvements! I got another one in the same shipment that is still looking alright with the same schedule but I am keeping an eye on it. I'm thinking I'll check out the roots on that one as well, just in case. Thanks again!

---------- Post added at 10:16 PM ---------- Previous post was at 10:12 PM ----------

Quote:

Originally Posted by SouthPark

That's very likely what did all this. The person that put it there most likely have their own watering plan, where they know just how much water to apply when they do water.

They probably shouldn't have put that foam plug into there in the first place - in my opinion. They can do it for themselves to grow, but shouldn't do that when they send the plant away to somebody.

It was one of those seedling plugs I think, they just plopped it in a new pot and filled with bark. Seems like a less than ideal way to do things, doubt I'll be buying from them again.

Quote:

Maybe a spray of thiomyl on the whole plant prior to repot could be beneficial too - just in case.

Hmm, I don't have anything like that, looks like something I should have in the toolbox "just in case"! Thanks!