Catasetinae Repotting
 

Hello all:

I discovered this year that the catasentinae family is for me and I have acquired almost 20 of these plants mostly from SVO. (Thank you Fred Clarke!).

All of my current plants are in their 2.5" plastic nursery pots in 100% sphagnum and have begun to spike / drop leaves. After debating semi hydro I have decided these will all be planted in 100% sphagnum in 4" terra cotta pots.

Question: I know the instructions are to wait until roots are 3" long in the spring before repotting but considering I will just be pulling their nursery pot and dropping them into a larger container and filling around the existing sphagnum with the same kind of potting media, is there any harm in me doing it now?

Also regarding watering / fertilizing, I have stopped fertilizing on November 15th and reduced watering. I let the plants become fully dry for a couple days before watering. Does this sound about right for plants dropping leaves and throwing up spikes?

Thanks!

Strictly speaking you can repot whenever you like. You want to wait at least until the roots are that long before watering. Starting last season, I wait until the mature bulb from which the new growth forms shrivels before watering. Apparently once the roots find water they "get lazy" and don't grow as much. The longer until they find water the more root mass forms. I was rewarded with 4 spikes on my Fdk Enter Light, so I'll be sticking with that regimen. Fwiw I'm an ardent supporter of s/h, and the vast majority of my plants are kept in it. But not Catasetum. I prefer the layered substrate method, where I fill the pot about 2/3 with regular composted cow manure with a layer of whatever on top. Last year I used cedar mulch which is much less expensive than even the bargain basement Mosser Lee Sphagnum I previously used. I don't think it's super important what the top layer is, as long as it's open, airy, and dry before the roots get long enough. Once the roots are down far enough to reach the manure they're ready for all those nutrients. Once I start watering, I keep the pots in trays with a few inches of water in them until the leaves start to yellow. Then I start the process of drying out the plants for dormancy.

No! You want to wait until the roots are 4" long to start watering. If you repot when the roots are this long, you'll snap them off and ruin the first flush of roots, which can be a major setback for the plant.

There's really one appropriate time to repot these guys: during dormancy. You want to have them all potted up before the roots start growing in spring.

Here's a video for potting in the PET method (the layering method mentioned by Subrosa): PET potting method for Catasetums- English - YouTube

One thing I forgot to mention. If you plan on keeping them outside as I do, putting a large heavy rock at the bottom of the pot will help prevent the plant from blowing over. All that vigorous growth makes a good sail!

Thanks for all the great advice. I will re-pot all my catasetinae into PET pots as they enter dormancy and will not water until the roots are at least 4" long and the bulb has shriveled a little.

Regarding the bottom later for the PET method, will LECA work?

Thanks again to Subrosa and isurus79

I don't see why it won't work, but at least for me it wouldn't be optimal. When they're in active growth, Catasetum are about the greediest feeders of any orchids I'm aware of. Even while growing in cow manure I'll fertilize them once in a while with the same strength of fertilizer I use on "regular" plants, 1tsp/gallon. It would be too much work for me to try to keep one fed enough in leca to reach its full potential.

Yes, any inorganic media would work! If you plan to have these guys sitting on a bench, adding something heavy to the bottom layer (like a rock, as Subrosa mentioned or small rocks) might be a good idea. I hang my plants, so they're less apt to tip over when fully leafed out. They get top heavy!

Will Catasetum need to be repotted every year with the PET method or can I get 2-3 years by using a large diameter pot?

You can get a few years with the PET method, assuming your plant doesn't get immensely huge in a single season and outgrow the pot! lol I joke, but it happens!

Yet another re-potting Catasetum question.
 

I have never seen this before on any of my plants.
The new growth has always started at media level but this thing is a good 4-5 inches up the pseudobulb.
What do I do? Just leave it there and let it find its own way to the media when I re-pot (usually mid-late April) or could it be safely removed and put in the media?
FWIW- There is a "normal" new growth unseen in this pic at media level on one of the other bulbs.