I have had the strangest experiences with petrocosmeas this winter. The older ones that have done well for 2 or 3 years are all suffering, and P. forrestii has had a near death experience. I had to take it apart and restart it. There are 2 new plants from little offsets I planted up this summer that are still very small. The rest of those leaves failed, but leaves of P. G25KC00 [not rosettifolia as some plants are labelled] started several new plants in just a couple months.
Photo of P. forrestii
Messages on gesneriphiles confirm that this Petrocosmea, P. G25KC00, produces new plants from leaves easily. My new plants that lived from the convention and from another local grower are growing fast [for Pets] and they have lovely flat rosettes. They seem to prefer brighter light than than older ones, warmer temperatures, and all of them are planted in little cylinders to let the leaves stick out over the sides. It's very tricky to keep them moist but not wet.
I'm still learning how to get the little offsets going, and they seem to grow so slowly. I can't give them the very cool temps in the winter that are said to cause prolific blooming. I think these and the mini Sinningias would be the most popular gesneriads for AV growers. They take up very little room, they will grow under lights or the right windowsills, and can be easily propagated. So much fun in so little space!
Many thanks to Charles H. for this article. Please remember to leave comments and questions for the authors.