Question
Sanny's Phal
My white phalaenopsis orchid's bottom leaf was turning yellow, which I initially believed it to be normal aging. Now I see a large dark spot and it concerns me. The rest of the leaves appear normal as of now.
AnswerSanny, once a leaf dies, its natural protection against fungal affection is reduced. Added to this, I notice that the plant is in moss which creates higher humidity which promotes fungal and bacterial growth. From what I can see, this still is a natural process (such as leaf decay in the autumn when they fall from the trees). I would not expect this to spread and the leaf is ready to fall from the plant. You may be able just give the leaf a twist when it is ready to fall and it will come off from the plant and, with it, any fungal or other infection.
If this begins to occur with other leaves in the next few months, then, I would suspect root decay and the plant will need to be repotted in fresh orchid potting mix. For now, however, do not panic and let's assume that no further leaves will be lost in the near future.
