Stanhopea wardii - yellowing pbulb

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Originally Posted by rbarata

Do you see in the plant any signs of a lack of fert?

Yes. The older pseudobulb is dying so it can supply nutrients to the younger growth.

This group of orchids requires much more nitrogen fertilizer than some others. In general, any plant with relatively larger leaves than its relatives will require much more nitrogen fertilizer than its smaller-leaved relatives. These plants have a lot more tissue to produce.

[rbarata]

I see... My interpretation is that, as those two old pbulbs are the original, offered to me as pbulbs with almost no roots nor leaves, they were used to supply nutrients for the establishment of the new plant.
Also a good indication is that, from the two new pbulbs that have grown since then, the youngest is the double in size from the older ( not mentioning the fact that the pot is full of roots under the medium and that I fertilize in almost every watering).
So I think the plant is growing well, slow but steady, which is expectable in a young plant.

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When Stanhopeas are happy, they do not grow slowly and steadily, not even a young plant. This is a "damn-
I-just-repotted-that-last-year" plant.

[rbarata]

So, what can be wrong?
It has a new growth going on but, as I'm not at home, I don't know how it is now.
Is has grown a new pbulb each year.

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Here is an older message from an expert:
Stanhopea wardii - yellowing pbulb

[rbarata]

So, do you think I should increase fert concentration?

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Yes. Manfred recommended 125 parts per million nitrogen at every watering, every evening during the summer growth period.

Using this, that would be 0.62ml of 20-20-20 powder per liter of water, or 1/2 teaspoon per gallon. Every day. The low-fertilizer thinking applies to slowly growing orchids, not things like Stanhopeas and Catasetums, which can grow almost as fast as sunflowers.

[rbarata]

The 125 ppm is the concentration I'm using (N 13%) but I don't water every day to avoid rot (as is still too young, it's in that plastic pot).

[isurus79]

I don't know, looks fine to me!

[rbarata]

It also looks fine but the concern is the growth rate.
This is my first one so, when ES tells me it could grow much faster I believe him and start to think what can be done.