Cattleya: Flower Sheath and Dormancy.

[Manfred Busche]

Hello there.
A very good book states that, after a Cattleya plant
has produced one or more Flower Sheaths, the plant
goes dormant i.e. requires a 'Rest Period'.
That book sounds very clear to me - but amongst the people I know, there is nobody who cultivates his/her plants accordingly. However, many 'complain' about empty Flower Sheaths !!
My question is:
Dormancy after appearance of Flower Sheath required...
...(a) for all Cattleyas ?
...(b) not for all, but indeed for some?
...(c) not at all?
I hope that one or the other of the knowledgeable Cattleya Aficionados out there will share what they know; thanks very much in advance.
MANFRED.

[SP2340]

You got some good questions, it's too bad nobody could answer them. Lets see if more people come across it this time.

[Becky15349]

I don't think that most cattleyas, being from tropical regions, actually get rest periods in nature. I suppose there are times when the rainfall is lighter, but humidity is always high, so I don't get why people think they would need a rest period - but who knows, maybe it helps them initiate buds? I really don't know.

[isurus79]

I always thought that meant that the plant was resting for a short period of time to recuperate from growing. I doubt the rain stops pouring during this time in the natural habitat. This rest is often very short and not as severe as a winter dormancy (unless the plant finished growing before winter!). Thats what I always thought, anyway.

[Royal]

When talking about orchids, I hesitate to say "always" or "never" so I'd go with answer B.

[WhiteRabbit]

I have read recently that some species do require a dry winter period.

I have a mystery catt - the only time it has ever bloomed for me was after being completely neglected for several month from late Nov - late spring.
So I would believe that some probably do require a bit of a dry period.

Tho 'rest' can also mean the plant does rest - many of my orchids go thru a period of sometimes a couple months after finishing blooming where they appear to be doing nothing - then suddenly - new growth starts popping out

This is a great topic as I would certainly like to hear more about it - I definitely do need help blooming catts lol

[Manfred Busche]

Hello.
Thank you, thank you, thank you for your comments.
...not fully conclusive yet though, right..? Shall we invite, for mutual benefit, further advice ?...
Info from my side first ::
One of my few Cattleya plants grows well but does not flower.
The label reads "Cattleya dowiana aurea".
Country of origin Costa Rica / Panama, country of purchase Brasil.
The plant at this time has lots of roots + 16 plump pseudobulbs + 16 leaves + 16 flower sheaths, 3 of which are green.
Except if Orchid Board members suggest otherwise, I will soon take action as follows :
place plant into plastic bag, close tightly and place plastic bag into refrigerator, keep there at 14°C for 72 hours and then hang plant into reasonably bright light without water - until bud shows ...
Any comments ?
Manfred.
The book mentioned above gives valuable information on general orchid cultivation ::
"Orchids for everyone" / Jack Kramer, ISBN 0 86101 939 3.

[catwalker808]

Manfred. Don't put the plants into your refrigerator unles you plan on making a salad. C dowiana is a summer bloomer. For those of us in warmer climates summer comes earlier ... spring also. I mention spring because your spring (the time when your sheaths probably developed) also came later.
If your plants have sheaths (especially some green sheaths) it means that they are probably on schedule for summer blooming. The green sheaths mean they will probably be a little later than here in paradise.

The dowianas are very seasonal and they give you lots of warning with the sheaths. If anything, you need brighter light.
Since your thread started with cattleya rest periods, here's some info.
Cats, in general, don't require a rest period. However, depending on climates where they are being grown, there are periods of the year when they are putting out active new (soft) growth. Then this growth needs time to harden off. For many species, the most active growth period also corresponds with the emergence of new roots. Some plants ONLY produce new roots with new growth.
The hardening of new growth can take several avenues. For some plants the maturation is just that, hardening ... as the canes change color from light green or greenish-purple to an overall duller or greenish-brown color. For cats such as the standard (or larger) caned cats (and related species), when grown in temperate climates, the active summer growth matures, then in the cooler temps of fall, the pseudobulbs start to swell to a large size.
These canes are storing up sugar and whatever nutrients and might fatten to 2-3" in diameter. C walkeriana produces slender canes in year round warm climates. In temperate climates, the canes faten up and become very rounded.
In the meantime, the plants do not produce new growths. You could call it a rest period, I guess, but they are just less active because of the season with lesser light and cooler temps and don't require much feed but they do require water depending on temps. In contrast, those of us who live in paradise have active growth much of the year, but with never the huge fat pbulbs of temperate climates.

Temperate climates also produce slower emerging flowers which are often larger and crisper than flowers which emerge quickly in warm temps. The often last longer in cooler temps ... provided they don't dry out from the cold air which holds less moisture.
Having said all of this, general advice would be to give your plants more water and feed during the warmer more active growing months. In the colder Germany winter months, the plants are less active and your plants will probably only need enough water to keep them from drying out and the pbulbs and roots from shriveling. You can kill a cats quickly with soggy roots. It takes a long time to kill them from drought.

[Cookiemonster]

OMG DO NOT PUT IT IN THE FRIDGE! Trust me on this one, it will not end up well....

Not all Cattleya/Laelia species come from the same region and experience the same conditions. There are some similarities like humidit -but here and there but there are some stark differences regarding lighting, temps, rainfall ect.
Some require dry periods in the winter which includes light misting, or right after blooming waiting for the new growth to emerge.

Do a little bit of research into the species you are growing and try to mimic their natural environment as much as possible

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[Manfred Busche]

Hi ... and thanks to all of you for your contribution .
More Info from my side ::
I grow in Java / Indonesia, in a warm climate where the weather provides for 6 months of rain and 6 months of no rain.
When the mentioned C. dowiana arrived, it had 3 pseudobulbs, it's roots damaged in transport.
I placed it in a clay pot with big holes, on top of chunky pieces of fir bark and hung it into light shade and, after the first new leaf shoot sprouted and had developed roots, subjected it to my Stanhopea regimen - spray until drench with water laced with fertiliser, every day if the day is sunny ...
Within 2 years this plant has grown 16 pseudobulbs + 16 leaves + lots of active roots. Few roots grow into the fir bark, most grow sideways to be 'air roots'. Customary for this plant, each leaf comes with a flower bud sheath, which dries up after some 4 weeks ...
At http://www.orquideas-katia.com/orqui...AS/COL 001.htm, we can admire a C. dowiana grown by others.
My plant is taller and bigger, and keeps growing but does not flower (so far) ...
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catwalker808 says (!THANKS!) that C. dowiana is "seasonal" and that flower sheaths indicate that flowering would be forthcoming in "summer", and that the pseudobulbs (canes) need to harden / ripen...
(a) In nature, the proces of "harden & ripen" probably occurs when the plant undergoes a dry season ...
.....I have 2 seasons here :: a rainy season and a dry season; I could easily subject a Cattleya plant to a
.....DRY SEASON, if that would cause the plant to flower.
(b) However, the plant in this photograph shows very neat and pretty pseudobulbs, color like Granny Smith Apples,
.....which obviously have undergone no "harden & ripen", but ló and behold (!!), the plant does flower !!
.....But - does it do so regularly / every year ??

My conclusion ::
-------------
Any adult species orchid should regularly flower once every year.
To persuade my C. dowiana to do so, I will subject it to a DRY SEASON, so that the pseudobulbs can harden and ripen,
as catwalker808 says ...
Thanks to you all.