Dendrobium dropping leaves - Orchid Board

Islander · #1 06-26-2016, 05:46 PM

I am a new member. I started about 2-3 years ago with a few orchids. This is my first Dendrobium. It is dropping leaves like crazy. Don't know what the cause is. Notice that light is shining through the spots on leaves. Would appreciate your advice. Thanking you in advance. UPDATE: I have added a photo of our Den Suree Peach when I purchased it 2 months ago.

silken · #2 06-27-2016, 11:55 AM

Welcome to Orchid Board. Your plant looks reasonably healthy. What I can see of the roots look good too. Can you expand on how you are growing it, how much light, how wet is it kept, etc. Have you had it long? Since Suree Peach isn't a registered name, it is hard to say what type of Dendrobium it is. Do you have a photo of the blooms? This would at least say if it is a Phal Dendrobium (needs warmth) or a Nobile type which needs a cool dry rest in winter in order to bloom.

I often get some spots like that on my Dendrobium leaves and really don't know why. Make sure there are no spider mites which are almost invisible. You can see them with a magnifying glass or wiping the leaves with a tissue and then looking for little dots on it (often red ones). Some make very fine webs on the backs of the leaves and in the crotches of the leaves. Holding up to the light will help.

If no bugs, it may be cultural. Also many Dens shed their leaves, but on new growths they should hang onto them for about a year.

Hopefully with a little more cultural info from you and maybe a picture of the bloom, we can give you some help.

campchi · #3 06-27-2016, 12:29 PM

Those bumps on the leaves worries me, i think you might hav some form of mites. Like the above post, rub it with alcohol to see if you see any red dots. Also good to do a systematic treatment just in case. Other than that, your dendrobium looks healthy

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silken · #4 06-27-2016, 01:25 PM

Quote:

Originally Posted by campchi

Those bumps on the leaves worries me, i think you might hav some form of mites. Like the above post, rub it with alcohol to see if you see any red dots. Also good to do a systematic treatment just in case. Other than that, your dendrobium looks healthy

Sent from my SPH-L710 using Tapatalk

One thing I have heard more than once, not sure how valid it is, but supposedly Dens do not like systemics with imidacloprid in them. I've never really wanted to test the theory on any of my few Dens!

rbarata · #5 06-27-2016, 01:53 PM

I treated my den with imidacloprid due to a heavy infestation of mealy bugs and nothing happened to the plant... I can't say the same about the bugs.

wintergirl · #6 06-27-2016, 04:46 PM

I use 1/2 rubbing alcohol, 1/2 water and a touch of dish soap. Works really well. Treat once a week x 3 weeks and they will be gone without harsh chemicals.
Spray complete plant. And let it sit x 15 min. Repeat then rinse with water.
Sometimes if I don't have alcohol I will use mouth wash (any kind not just yellow listerine).

Islander · #7 06-27-2016, 05:55 PM

hi, I have added a photo of it in bloom to my original post. I purchased it 2 months ago. It bloomed for about a month after I bought it. I water it every 2 or 3 days. I have just been guessing at it's watering needs. There seems to be quite a bit of sphagnum moss around roots. It sits under an eve on our front porch on a table. It gets no direct or filtered sun. I do find VERY THIN spider webs on it every day & wipe them off with my finger. I thought they were cat hairs at first. I have saturated the leaves with Garden Safe brand Fungicide3 twice in the past 7 days. I cover the bark so spray does not get into roots. Maybe they are in the bark? I have not seen anything with a magnifying glass. I did wipe the leaves with rubbing alcohol 3 days ago. There is a new stem rising out of the bark & it is growing rapidly. Thank you so much for taking the time to help me.

---------- Post added at 05:55 PM ---------- Previous post was at 05:47 PM ----------

thank you for the great info.

silken · #8 06-27-2016, 06:12 PM

Dendrobium-Phalaenopsis Care - Akatsuka Orchid Gardens, Volcano Hawaii
This looks like the Phal type Den. Attached is a link to some growing instructions. It does sound like you could have spider mites if you are seeing webs.

They like fairly good light and if not mite damage, ithe spots can also happen if water is left on the leaves in cool temps. This link gives comprehensive info on their care. If new growths are forming, it may be a good time to repot in a medium with less moss as the roots need to breath a bit. They do not like over potting.