What causes the leaf sheaths of new orchid shoots to dry up?

Repotting during the growing season or poor roots on the mother shoot can cause the leaf sheaths of newly sprouted shoots to dry up prematurely.

If the outermost one or two layers of leaf sheath on the current year's new growth wither, and it is not due to the seedling stock or fertilizer and water, then it is not a disease; it should be considered a normal phenomenon of the plant being not robust and lacking vitality. Do not worry about it too much. It is recommended to clean away the withered sheaths, plant it appropriately deep, and do not use fertilizer before it has regained vigor. Make the potting mix even leaner than the current one, and let it progress gradually, accumulating strength before it bursts forth.

Regarding this problem, I just repotted and took a look, and at least one of the causes can be said to be the root replacement of the old shoot that produced the new growth. All the leaf sheaths of my new growth dried up, and they tightly wrapped the base of the leaves. After taking it out of the pot, I found that the old shoot had become completely hollow because of repotting and changing the medium, becoming a burden on the new growth.

Bury it moderately deep, with the potting mix covering half of the pseudobulb; then spread a layer of red-bean-sized Kanuma-like stone over the pseudobulb. This should be enough. Adjust the watering frequency according to the environmental conditions.

When this problem occurs, it will affect the growth of next year's new shoots. You can only cultivate it slowly and carefully, and do not use fertilizer.