The board says you have 2 responses. However I can't see them. Sorry if its repeat info. I have a lot in s/h, rock pumice etc. I just let the resevoir run dry. I don't have a den nobile in s/h so I can't answer to that specifically. Mine is in a mix of pumice and tree fern. not s/h style though. If it enjoys a rest then let the resevoir dry out. Rock takes longer to dry for me than I ever imagined. It looks dry but it isn't

Clara

Claritamaria: GardenWeb is deliberately blocking responses that reference Orchd Sourse Forum [sic]. Try googling "semi-hydroponics forum" and "winter rest" as suggested by early_bird_2007 whose post is blocked. Hope this helps, alvin

Alvin
Thanks. Never saw it before. Can you see the posts?

To your post, I don't do anything different w/ s/h than I would with any other substrate. It is what it is, something to keep the roots in moist, tasty shape. Follow the culture and your micro-climate.
Clara

Hi Claritamaria:
Sadly I can't see the 2 blocked posts now either [so this must be how it's like using Internet in fascist media-controlled countries!] But I did catch the responses before the GardenWeb bot blocked them for their Orch*d Sour*e For*m [sic] weblink. early_bird_2007 had kindly advised me to google "semi-hydroponics forum" and "winter rest" which got me the exact info I needed. Essentially, winter resting in s/h culture amounts to flushing the plant (of fertilizers in the watery substrate) & holding all fertilizer application altogether starting end of August (Northern Hemisphere), but watering with H20 only as usual.

Thank you so much for your great tip about how *slowly* lava rock dries - I didn't know this before. I use lava rock for media in the bottom 1/2 of all my potted orchids as I'm an over-waterer. Top 1/2 is anything from fir bark to sphagnum moss. So thanks for the great tip! alvin

The method is not generally known in the hydroponics community, it is only an orchid thing, known by few outside the forums so googling won't get you far.

I have been growing this way for nearly a decade and give lectures on it at orchid societies etc. It can be argued that if you let the pots go dry then you are not using the technique, and hence the name, but the orchids that need a rest are somewhat of an exception. In a greenhouse you can usually not give them a rest and still get somr flowers. This may be a bit dicy if growing in a house.

The plant form and function is not radically different after being grown with the technique, so if you stop watering for the winter, or let the pot go dry through negligence in the summer the plant will not be harmed. In my experience with Den nobile species and hybrids it is the temperature drop that gets the flowers going, and lack of nitrogen that holds off new growth (A cold snap late in spring can bring on flowering of growing canes). Water is usually associated with nitrogen by releasing it from dry organic medium even if you are not fertilizing, so a dry pot means no nitrogen for the plant. The pellets don't hold on to/build up fertilizer salts the way organic medium does because they get flushed each week so it is not that big of a deal if they stay wet a little longer.

The pellets hold a great deal of inner water so letting the pot go dry is not really providing the plant with a dry pot. If you flush the pot with fresh water (you can do this a second time in a couple of days if you want to feel better about it) and just let the plant sit it will keep its leaves for a while and photosynthesize until after new years, gaining energy for flowering. When the pot hits critical dryness leaves will start to drop and then you should get flowers on time. The trick is to get the mature canes as much light as possible while its leaves are still on to support production of more flowers.

I never got the hang of Den kingianum. They seem to need real stress to bloom, and minw were always in the wrong place and so got watered and fertilized way enough to stop them from blooming. The year I transfered them they bloomend well even though I fertilized them so I'm assuming it was the stress that year.

If you would like further info or more answers, I'd suggest that you try here! :~)
(That is, if you haven't already.)
First Ray's

Just do a Google search and then look for answers or ask.
After all, he did start the whole thing to begin with! ;~)

I'm still not sure if I should send hate mail or thanks!
It's all his fault that I have so many orchids!
It's been the absolute worst case of enabling that I've ever seen!!

He used to post here frequently, but I'm not sure if he has recently.
I've been busy, myself, and haven't followed everything!

Scott

Thank you spiced_ham and scott361 for the great advice!