Catasetum not dropping leaves

[calvin_orchidL]

Hey everyone,

I have a catasetum hybrid, and it doesn't seem to be dropping it's leaves - should the plant be allowed to go bone dry? I left it without water for a month, but instead of dropping leaves, the pbulbs started shrivelling, signalling to me that it isn't ready for dormancy. Now I just spritz the sphag a little once every 3 weeks...should I just stop watering all together?

[kavanaru]

Calvin,

if the pseudobulb is already mature, you can stop fertilizing (as a thumb rule: start this by Nov, 15th) and start reducing watering by half (as a thumb rule start this by Dec., 1st). By January 1st all leave should be fallen. If not, then just stop water completely by jan, 1st and let the leave dry out.

If the PBs are not yet mature, I would continue watering and fertilizing until the plant decides it wants to go dormant.

I know some Catasetinae, which just refise to go dormant (have seen this mainly in S/H), and which just start a new growth before the leave of the older plant are fallen. Now, I have one cycnodes doing this. It will have no rest at all this year!

[isurus79]

FWIW, I have also talked to some Catasetinae growers (Gene Monnier and others) who feel that if the temps do not go below 55 degrees F, then your Cats don't even need a rest. I'm experimenting with that this winter.

[kavanaru]

Isurus, that's also another approach, but a bit risky...

on the other hand, Catasetum always goes dormant in nature, at actually quite high temperatures. Normally during the dry season, which is also the hottest season in the amazona basin... the trigger to dormancy is lack of water...

[isurus79]

Ramon,
You're right, it is a risky method of growth! That's why I am experimenting on a few of my less expensive Cycnoches and others.

Would a wild Catasetum stay growing if it were watered (by a person, for example) during its dry season? I was told that these plants will just keep growing (and not rot) if the air is warm and water flows. Basically, if the plant is watered in culture with cold weather, it will rot. If it keeps ample water with warm temps, it just keeps growing.

Anyway, sorry Calvin for the thread highjack! I should have mentioned in my last post that Ramon's advice is what I would have recommended as well, but I drank too much coffee this morning and got a little over excited.

[kavanaru]

I can only speak for Ctsm macrocaropum and Ctsm pileatum growing on the trees at my mother's house in Venezuela (very strongly marked dry and rainy season in that part of Venezuela: during the dry season most trees loose their leave too). There are many other orchids growing next to them, and these need to be watered all the time (specially during the dry season). both Ctsm species received also quite a lot of water during this time (this is done by the gardeners), and they go dormant independently of whethere watered or not. I think it is a combination of higher temps and drier air, which initiates the dormancy. they do not start growing again until just before the rainy season starts again (temps are slightly lower)

[calvin_orchidL]

Thanks for the input, guys. My plant is grown somewhat intermediate, although the temps do likely drop 5-7F during the winter season. I'll keep observing and water if the pbs look like they're shrivelling too much. Hopefully nature will run it's course.

[brsucculents]

Originally Posted by isurus79

FWIW, I have also talked to some Catasetinae growers (Gene Monnier and others) who feel that if the temps do not go below 55 degrees F, then your Cats don't even need a rest. I'm experimenting with that this winter.

I realize this is an out thread. This warm weather and many of my Catasetinae with leaves this year make me wonder how Stephen's experiment went. I found it interesting that Katrina doesn't force here seedlings into dormancy. So is there a need for them to go dormant to initiate new growth or bloom? I do have several small divisions of Fredclarkara that have leaves and are starting to put out new growths

[Yazz]

If they're putting out new growths, I wouldn't force anything on them. Let them do their thing.

In Houston, not all cats go dormant. Remember to repot them in the spring.

[My Green Pets]

I would guess that a plant which has evolved a dormant period would eventually experience decreased vigor if grown continuously all year.

I would not fight the plant if it were showing signs of growth, however.

Perhaps its cycles are a bit off. I would not expect a plant to go dormant until new pbulbs had completely hardened, but a plant grown in a warmer place, used to a longer growing season, may take some acclimatization if moved to a more northerly location.

$0.02