Clowesia/Catasetum root rot!

[chickazilla]

Hello,
I'm fairly new to this forum and would greatly appreciate any wisdom/advice. I've searched hi and lo on the internet for some advice on this matter and can't find anything that helps. I recently purchased a Clowesia (Rebecca Northen) with one very shriveled bulb but two very healthy new bulbs with lots of leaves. (see pics) It also used to have very healthy roots. I repotted in a coconut bark medium because I read they like a lot of moisture until they go dormant. Well, we had some intense heat spells here in the 90s-100s for about 2 weeks and given the severe shriveling of the oldest bulb, I over watered and rotted ALL of the roots. I know, I'm an idiot. My question is what I can do with the plant now, and especially to encourage new roots. I have it sitting on damp sphagnum moss right now but I've also read that it's fine just to replant rootless catasetums in dry medium and leave it dry. PLEASE HELP OB-1, you're my only hope! I really don't want to lose this plant and would greatly appreciate any help. Thank you.

[Roberta]

Originally Posted by chickazilla

Hello,
I have it sitting on damp sphagnum moss right now but I've also read that it's fine just to replant rootless catasetums in dry medium and leave it dry. PLEASE HELP OB-1, you're my only hope! I really don't want to lose this plant and would greatly appreciate any help. Thank you.

It's not going to do much (or any) root growing at this time of year. Dormancy is near. Don't worry about the roots... it'll run on those pseudoblbs for an amazingly long time. For now the damp sphag may help keep it from dehydrating further, as long as it still has leaves. Once the leaves start to yellow and drop (and they will. Force of nature... it's that time of year) stop watering. Just put the plant in a comfortably warm place (like the house... they don't like to go much below 55 deg F when dormant) and pretty much forget about it until February or so. This hybrid will bloom on bare pseudobulbs in the the late winter or early spring, and only after it has done that will it even think about new growth (which will also produce new roots... the previous year's roots are, at that point pretty much useless even if they existed) Resist the temptation to water when you see new growth... wait until the new growth - and new roots - are at about 3 inches long, then you can start to water. That will be somewhere around March or April.

If you want to repot, the time to do it is in winter, while it is dormant - but no water! (If you are using sphagnum, it will need to be damp just to work with it, but only barely, and then no more water)

[chickazilla]

Thank you so so much! I thought I destroyed it. I will follow your instructions. Yay!

[Roberta]

For general instructions on Catasetinae, check out Sunset Valley Orchids - Catasetinae Culture
Sunset Valley Orchids, owned by Fred Clarke, is one of the top breeders of this group in the world. Fred Clarke, reachable through the website, is happy to answer questions, and he probably knows as much about this group as anybody on the planet!

[estación seca]

This group of orchids tends to make roots only once a year, just before they start growing in spring. Repotting at any other time is not a good idea.

[katrina]

I suspect your roots died not because of a lot of water but more likely due to bad timing on that repot. When in active growth...you really can't over-water this group.

Roberta is right...no water now. With no roots, it can't absorb anything anyway AND you risk rotting the growths.

I've had mishaps with this group and sometimes they will make back-up growths after trauma. If it does make another growth during winter...give it as much light as you can and start watering and fertilizing, once the roots are a few inches. I water all my ctsm a little through the winter but they have active roots whereas one with no roots would get no water until there is sufficient new roots.

[bil]

Originally Posted by katrina

I suspect your roots died not because of a lot of water but more likely due to bad timing on that repot. When in active growth...you really can't over-water this group.

Yeah. I tend to agree with this. I wouldn't dream of reppotting any time other than when they are in dormancy, and mine just sit in water all day every day, and don't turn a hair..

[DeaC]

Hi...Roberta's suggestion is great place to start.I've recently gotten plants from him(including 2 R. Northen). But The American Orchid Society also provides good info.

[Roberta]

Chickazilla, since you live in Los Angeles, it's an easy hour and a half trip to visit Sunset Valley Orchids in Vista... they will have an Open House, I think, on Dec 2 (not sure if it will also be Dec 3), but several San Diego-area growers have open houses that weekend though the notices have not gone up yet. Check the website in another month or six weeks.

[katrina]

Originally Posted by bil

Yeah. I tend to agree with this. I wouldn't dream of reppotting any time other than when they are in dormancy, and mine just sit in water all day every day, and don't turn a hair..

Yep, mine sit in saucers of water once they are big enough to be at full watering levels and they maintain wet-butts until the growths start heading toward dormancy.