Why my orchid leaves are yellowing? - Orchid Board

KC Kam · #1 08-12-2018, 10:49 PM

Hi All,

I have a cattleya in my care for 2 years...it bloomed in the same spot for 1 time just that its flower is slightly smaller compare to the previous spot. Recently its leaves turn yellow and i am worried because the yellowing leaves does not come from the oldest bulb + yellowing leaves comes from a few bulbs at the same time. Is this under water or some kind or fungi / bacteria attack?

Please help.

dounoharm · #2 08-13-2018, 09:27 AM

I would venture a guess, either natural ageing or too much sun....try putting a light screen over/in front of it....or move it to an area of more shade.....could there have been a change in the trees surrounding your space?

KC Kam · #3 08-13-2018, 09:50 AM

Quote:

Originally Posted by dounoharm

I would venture a guess, either natural ageing or too much sun....try putting a light screen over/in front of it....or move it to an area of more shade.....could there have been a change in the trees surrounding your space?

Hi Dounoharm,

Is too late...the orchid was dying. As shown in the picture, the pseudobulbs were turning yellow+brown and it is getting soft when i press it. I guess it is some bacteria infection. I have to cut those that looks healthy ones out...

One of the pseudobulb has i believed infected eyes...so i have to cut that out too.

I dont know what happen and how to prevent it in the future...

Roberta · #4 08-13-2018, 12:51 PM

I think you got it in time... the picture showing the cut looks clean (the dark part of the eye looks OK to me) Sometimes rot does get into the rhizome, and unless the bad part is removed fast, it can take the whole plant down. But I think you did the right thing.

Nexogen · #5 08-13-2018, 05:52 PM

In pictures posted yesterday, there are traces of spider mites. These small destroyers cause huge damage. If you do not use MITICIDES, you will be left without plants.

http://extension.msstate.edu/sites/d...005/bw0905.pdf

KC Kam · #6 08-13-2018, 11:42 PM

Thanks Roberta...a 2 years plant now become 2 small pieces plant..is like starting from zero again.

Hi Nexogen, i double checked. No traces of spidermite. Those white stains are fungicide that i applied on saturday.

Hi all, i suspect it is highly due to the rotten moss. The moss came with the plant when i bought it 2 years ago. The nursery was using it to increase moisture around the plant for it to root on the new medium. I believe the moss was broken down over the years and now i recalled there are some mild foul scent on it months ago just that i didnt thought it will cause any problem. I suspect bacteria developed and cause this damaged. It was my fault...lesson learn. I will replace all moss on my plant every 1-2 years.

Roberta · #7 08-14-2018, 12:57 AM

Moss on a Cattleya? Not so good. Catts need to dry out almost completely before getting watered again. Remount, and skip the moss. Then you can't over-water, even if it gets rained upon every day, it will dry out in an hour or two... Malaysia is very humid, so bare-root mounted Catts should be quite happy. With luck, the eyes will "pop" and you get roots right away... with new roots it will establish quickly.

KC Kam · #8 08-14-2018, 05:43 AM

Quote:

Originally Posted by Roberta

Moss on a Cattleya? Not so good. Catts need to dry out almost completely before getting watered again. Remount, and skip the moss. Then you can't over-water, even if it gets rained upon every day, it will dry out in an hour or two... Malaysia is very humid, so bare-root mounted Catts should be quite happy. With luck, the eyes will "pop" and you get roots right away... with new roots it will establish quickly.

Hi Roberta,

This is a cattleya nobilior. They need abit more moist environment compare to normal cattleya right? Correct me if i am wrong.

Thanks for the motivating and encouraging words.

Roberta · #9 08-14-2018, 10:35 AM

Quote:

Originally Posted by KC Kam

Hi Roberta,

This is a cattleya nobilior. They need abit more moist environment compare to normal cattleya right? Correct me if i am wrong.

Thanks for the motivating and encouraging words.

I truly don't know how much moisture they need. (I have one, but not for long enough to say that I know anything about its culture) But it is from Brazil, in an area that gets a lot of rain in the summer, but is drier in winter. It grows on the sides of trees - a very well-drained environment! Where you live, I don't think that moisture/humidity is going to be an issue. It needs to dry out after it is watered. In winter, in fact, you need to reduce watering (not stop it, but definitely less often) - in its habitat, rain becomes less frequent and it depends more on the humidity/dew. It does grow in a warm area, so your temperatures should be fairly ideal.

estación seca · #10 08-15-2018, 12:40 AM

Cattleya nobilior comes from a part of Brazil with very wet summers. It grows on leafy tree branches in bright shade with no moss. In winter it is completely dry and gets no rain, almost no dew. The trees drop their leaves and the plant gets a lot more sun.

It seems to do better in cultivation if it dries out completely between waterings. If your summers are very wet, consider removing the moss, and letting the plant grow on a bare branch.