Brownish spot/patch on Dendrobium stalk
 

Hi,
I am a beginner Dendrobium grower. I have recently purchased a Dendrobium Nopporn Pink 'White Mutation' Orchid. I have noticed a brown patch and a brown spot on the stalk and was wondering if I should be concerned. The brown patch encircles the entire stalk. Any help would be appreciated. Thanks

I dont know that much about stemmed dendrobiums,

But it looks like regular coloration that appears on the stems of some dendrobiums.

Hi Saka, I have edited my post to include that the lower patch encircles the entire stem / stalk. This plant has 2 stalks and the other is spotless. I have also looked online at dozens of dend. and have not seen one that has these marks on them.

Which one is the oldest? The spotless or the other?

Two more questions:

- How do you water it? From above?
- Living in Arkansas, what are your temps during the night?

Brownish spot/patch on Dendrobium stalk
 

I just purchased this orchid and received it yesterday per us mail so it is hard for me to answer your questions. The spotless one is taller but not sure which is the older one. It was sent to me bare root and a lot of the roots look unviable. My orchids grow inside under lights.

I just asked those questions to the seller and the following was her reply.

*sommerssecretgarden*

Never watered from above, least not how they are asking water never splashed and hit leaves was always watered at bark media, the spot one is older than the other cane, and the temps in my grow runs around 70-80 during daytime with nighttime around 65-70 and humidity was between 50%-60%.

Those temps are ok (for the summer).
The watering from above deposits water inside the areas where the spots are. It promotes bacterial development and, if temps are low, it might rot.

Some Dendrobiums lose their leaves from the older canes in winter. The flowers will appear on the leafless canes, as long as you provide the plant with the minimum water in winter, low temps (around 12ºC) and a lot of indirect light.

It seems from the photos your plant is one of those Den.

In the meanwhile keep an eye on it and see if the spots spread. If they do, cut the affected cane just bellow the lowest spot and apply cinammon on the wound (not the roots or you'll kill the plant.