advice repotting cattleya warnereii and BLC Ahchung Ruby
 

Hi Orchid friends,
I am an amateur grower. Last year I acquired a cattleya warnerii and a BLC Ahchung Ruby. Both are putting out new growth. I wonder though if I should be repotting them. The cattleya warnerii has many roots outside the pot. The BLC Ahchung Ruby topples over in its present pot. Also what potting mixture should I use? What size pot(s) should I aim for?

The time to repot Cattleyas is when new root nubs are just forming. When they're already a centimeter long it's very easy to break them, and I would advise waiting. If you don't have new root growth on the plants, you can stabilize them by setting them into larger clay pots with no additional medium.

What medium to use depends on your growing conditions and how much time you have to check on your plants. Very large chunks of bark, scoria, wine corks, perlite or pumice always work well if you have time to water every day or two. If you don't have that kind of time, you can use smaller chunks of similar materials.

You can also use long-fiber sphagnum moss with good success. Often people can reduce watering to once a week when growing in moss. Watering this is different from other media. If you water too often in moss, it is very easy to suffocate and kill roots. Many people keep their plants in moss separate from plants in other media to prevent accidental overwatering.

Some people repot overgrown Catts by dropping the entire old pot into a larger pot, and backfilling with new medium. This works well. Older roots in older medium aren't as important for most Catts; the newest roots are the most active in taking up water and nutrients.