| Q Last spring, I purchased a large plant of Dendrobium chrysotoxum from
a South Florida grower. It was in a deteriorated slatted basket, so in early March I
repotted it into another, slightly larger basket. Since it had been grown without medium,
I treated it the same way. Over the summer, I watered and fertilized regularly and the new
pseudobulbs are larger than in previous years. The problem is that the plant does not seem
to have made any new roots. When does this species make its new roots, or should I not
worry? A It has been my observation that this type of dendrobium will often make roots quite late in the season, well after you would normally have expected them. It is almost like they subsist on last year's roots and make new ones for the coming year while they seem dormant. I would not worry unless I did not see any roots on the plant in the autumn. Even then, with the increased vigor and size of the pseudobulbs you describe, a wait until spring may find this year's pseudobulbs making their roots as new growths come. — Ned Nash |
Reprinted, with permission, from "Orchids" - The Magazine of the American Orchid Society, February 2001.