Isabelia virginalis leaves yellowing and falling off

[Mikefromearth]

Hi all,

My Isabelia virginalis doesnt seem very happy. It's continuously growing new leaves, but the older ones keep turning yellow and falling off.

It's mounted on a stump in my terrarium up near the light. I water it every 2-4 days, mostly in the morning, and it dries by night time.

The environment is very humid, I would say 80-95% humidity. There is no air movement right now other than me opening the lid and blowing air in manually.

I have never fertilized the plant.

I assumed in the beginning the problem was over watering or too much moss holding too much moisture around the bulbs, so I removed 50% of the moss and started watering it less, but the problem persists.

Do any of you have ideas as to why the plant isnt doing well? If so, please help!

Thanks!

[King_of_orchid_growing:)]

Do you have a pic?

[Shiffdaddy]

I'm no orchid expert by any means but i am taking lots of horticulture classes in college and this is my understanding..

Nitrogen is called a mobile nutrient because it can be transported through the plant to help out younger growth. Lots of plants (again not sure if orchids are the same) draw nitrogen from their old leaves in order to compensate for a lack of nitrogen for new leaf growth. This will turn the old leaves yellow but as long as the new growth is still green then you are fine.

Maybe try giving it a strong nitrogen fertilizer once a month? Just my opinion. Anyone else have more information or would like to back me up

[King_of_orchid_growing:)]

Well, Shiffdaddy...

The reason I asked for a photo is because I wanted to find out if it was a natural thing for it to shed older leaves.

Some orchids naturally just drop older leaves and have the older pseudobulbs continue functioning normally until the newer growths have depleted the energy resources from the old pseudobulbs as well.

[Shiffdaddy]

ok ok, that makes sense.

[King_of_orchid_growing:)]

I forgot to mention...

I asked for photos because I also wanted to know if the plant was damaged. The person may not know that it may have been a messed up plant.