I am having a problem lately with new flower sheaths on my cattleyas
withering before they can develop. They turn yellow and papery and
they're done. What would cause this ? I fertilize weekly (weakly) and
water twice a week. They are kept in my basement at suitable cattleya
temperatures under 400 watt HID lights. Any suggestions, anyone ?

I am using a commercial mix of bark, charcoal, and lava rock. I think
watering twice a week is optimal, but perhaps I need to check the bottom of
the potting
medium to see how wet it is. I just had one plant with new shoots that
basically fell over. I suspect root rot there.

"Steve" wrote in message
...
Brian Corll wrote:
I am having a problem lately with new flower sheaths on my cattleyas
withering before they can develop. They turn yellow and papery and
they're done. What would cause this ? I fertilize weekly (weakly) and
water twice a week. They are kept in my basement at suitable cattleya
temperatures under 400 watt HID lights. Any suggestions, anyone ?


I also grow in my basement under HID lights. Most of my Catts will bloom
by pushing buds out of a green sheath. A few will have the sheaths turn
brown and dry and have the buds still appear later. There is one other
group that I have to watch. With those, if I let the sheath dry up, the
buds will die in the sheath. I have to watch the sheaths carefully. When
I see one start to turn yellow, I have to open it right away. I usually
just pull the tip apart and press on the top and bottom so I can look in
and see the buds. If I do it in time, the buds will be green and the
sheath will bloom. If I am too late, the moisture that forms inside will
have rotted the buds.
Keep in mind that a Catt that isn't quite strong enough to bloom will
often form a sheath with no buds. If buds are not going to form, the
sheaths will sit there for a while and then dry up. Could something
about your growing conditions be keeping the Catts too weak to bloom? I
wouldn't dare water most of my Catts twice a week or the roots would
rot. That depends on what you are growing in and how well it drains.

Steve

I am using a commercial mix of bark, charcoal, and lava rock. I think
watering twice a week is optimal, but perhaps I need to check the bottom of
the potting
medium to see how wet it is. I just had one plant with new shoots that
basically fell over. I suspect root rot there.

"Steve" wrote in message
...
Brian Corll wrote:
I am having a problem lately with new flower sheaths on my cattleyas
withering before they can develop. They turn yellow and papery and
they're done. What would cause this ? I fertilize weekly (weakly) and
water twice a week. They are kept in my basement at suitable cattleya
temperatures under 400 watt HID lights. Any suggestions, anyone ?


I also grow in my basement under HID lights. Most of my Catts will bloom
by pushing buds out of a green sheath. A few will have the sheaths turn
brown and dry and have the buds still appear later. There is one other
group that I have to watch. With those, if I let the sheath dry up, the
buds will die in the sheath. I have to watch the sheaths carefully. When
I see one start to turn yellow, I have to open it right away. I usually
just pull the tip apart and press on the top and bottom so I can look in
and see the buds. If I do it in time, the buds will be green and the
sheath will bloom. If I am too late, the moisture that forms inside will
have rotted the buds.
Keep in mind that a Catt that isn't quite strong enough to bloom will
often form a sheath with no buds. If buds are not going to form, the
sheaths will sit there for a while and then dry up. Could something
about your growing conditions be keeping the Catts too weak to bloom? I
wouldn't dare water most of my Catts twice a week or the roots would
rot. That depends on what you are growing in and how well it drains.

Steve

Brian Corll wrote:

I am using a commercial mix of bark, charcoal, and lava rock. I think
watering twice a week is optimal, but perhaps I need to check the bottom of
the potting
medium to see how wet it is. I just had one plant with new shoots that
basically fell over. I suspect root rot there.


Yeah, I'd do that. I can't imagine any conditions that would
require watering catts twice a week (at least in the winter) in that
type of mix, unless it were substantially more rock and charcoal than
bark. Your mileage may vary, if you had insanely low humidity and
really bright light, maybe twice a week is right. Might be easier to
increase the humidity and lower the light levels a bit though.

Many potting mixes look very dry on top, and are quite wet on the
bottom. Bigger pots (anything over 5" is big to me...) especially. Try
sticking a freshly sharpened pencil deep into the pot, leaving it there
for a few minutes and pulling it out. Another good experiment is (when
you are repotting anyway, spring is coming up), pull the plant out of
the pot instead of watering it. Examine both the bark and the roots.
Also remember that any mix with bark (or any other plant based material)
in it will behave differently as it ages. Old bark holds a lot more
water than fresh bark.

Happy gnu deer, everybody!

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit
LittlefrogFarm is open - e-mail me for a list )

do you know which type of Cattleya is doing this? i have several Catts that do this (mainly hybrids of Catt. aurantiaca and the species aurantiaca too) but i have found that if left alone and not dut off they ALL flower even though the sheath has gone brown weeks or even months before!

maybe yours are mungrels like mine are and will flower ok anyway??? dont reall know what to suggest otherwise, but i hope they are all ok!