Originally Posted by james mickelso (Post 580681)

Ease up on the watering if the media is breaking down. The flowers will last anyway with less watering. The important thing here is to keep the roots in good condition so when it is repotted it will respond well. The other important thing here is that the new growth is the future of the plant. You mention specimen size. That can be obtained as long as all conditions the plant needs are met. All the oncidium types have thin numerous root masses that are quickly damaged by wet conditions. The longer the wet conditions around the roots remains the more damage is inflicted. To keep the root mass healthy for the time it takes to grow this to specimen size the media has to be a type that breaks down slowly and dries quickly. If a bark is used it must be of a very hard variety like Orchiata. New Zealand fir bark is very hard and lasts for 3 or 4 years depending on conditions. Lava cinder, LECA, or other inorganic media are very useful in keeping the plant potted without disturbance. Oncidium type orchids do not like the root mass disturbed at all. The correct time to repot is when the new growth has grown roots at least 1 inch long. This gives the new roots time to grow into the media before fall's cooler temps. So get a good media for it, a pot that just holds the root mass with an inch or so to spare, and when the flowering ceases and new growth appears, get ready to pot and not before. Here is what the new growth and roots should look like when you go to repot.