Fert during "active growth" (C. spp)
 

Hi,

I've always had the understanding that fertilizing Cattleyas (and pretty much all orchids) should only be done during active pseudobulb/leaf development. My dowiana and amethystoglossa have just started to send out new roots from the newest pseudobulbs which are not currently growing. Should I continue to refrain from fertilizing?

For leaves and pseudobulbs what marks the start and end of active growth in terms of fertilizing?

Matt, I generally fert at very low rates year round.

You can keep fertilizing. Roots require nutrition to grow too!

My amethystoglossa just grew a large number of new roots also. It seems to be one of those cattleyas that grows a new pseudobulb first and then sends out a bunch of roots. Other catts do just the opposite, growing new roots just before a new pseudobulb starts. My amethystoglossa blooms around February and the books say that it rests before blooming. So it should be going into a rest period pretty soon. I fertilize most my hybrid catts year round but it might be a good idea to slow down some with species like amethystoglossa. If it doesn't get a rest period it will probably still bloom but the blooms should be better if the plant rests like it does in nature. Less water and less fertilizer for the next couple months may give you better blooms, but I'm not an expert on this species.

Tucker is absolutely corect in this. If in doubt you can continue to fertilize lightly. But too much nitrogen can impede blooming. Be careful. Of course the other line of reasoning is that no fertilizer won't do "any" harm at all either. Take your pick.