Question on culture

[gngrhill]

This is kind of a continuation of the previous thread on dormant catasetums. I have a new growth (tiny ) started with tiny little root nubs started. I know I'm supposed to wait until the roots are 3 to 5 inches long before watering . The problem I need help with is that the old roots are very tightly packed in totally dry spaghnum. If the new roots grow into that I will never be able to tell how long they are. Also, as the new roots grow, what should I do with the old roots that are so tightly packed ?Should I repot ? Into what medium ? when ? Any advice appreciated.