Can anyone tell me what is growing on my 2 Cattleyas?

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Both your Cattleyas are immature plants that will get VERY MUCH bigger. You will not be able to keep them in those small pots. They need to go into larger pots soon, or now, not the same size pot in which they have been growing. Most people keep mature plants like this in pots of diameter at least 6"-8" / 15cm-20cm pots. They look and grow better in even larger pots.

When you repot, select a pot big enough for about two more year's growth. By that time the bark will be breaking down, and it will be time to repot again. It is hard to tell what size pots to use when you are a beginner, but if the plant is now in a 3" / 7.5cm pot, and is that vigorous, I think you could go up to a 6" diameter pot now.

Breeders are developing much smaller Cattleyas that are happy in 4" / 10cm pots, and flower easily on windowsills. If you don't have room for many standard-size Cattleyas, you can look for mini catts or windowsill catts.

[King_of_orchid_growing:)]

You may put the existing pot in a larger pot.

The thing about Cattelyas is that while the older roots do die back during the rest period in the winter, not all of the old roots will die back completely. Repotting the Cattleya will not necessarily kill the older living roots unless they were badly damaged. New shoots will grow new roots and the older roots that are still alive will continue to grow for a little while longer until they naturally die off due to old age.