Winter Light Question

[jmoore3274]

I have a greenhouse that is situated in a way to where during the summer months it is protected from the harsh late afternoon sun. Come Nov I removed the shade cloth and tested the light to have an idea how bright the light is. I tested around 11am-12pm and I was getting around 6000+FC from the top of my benches.

Now because the photo-period was still rather long here in Maryland I decided to still keep my orchids and other shade loving plants on the bottom shelf of my bench system where they were receiving from 1000-2000 FC. They are doing well, bloomed and sending out shoots.

Would it be safe to move the Orchids to the top of the bench now? I have not tested the light but I'm getting around 5-6 hours of direct light which I believe will still be in the 5000-6000 FC range.

What do you greenhouse growers do during the winter months when the photo-period is shortening?

Here is my current collection:

*Bc. Angel Lace
*Sand. Black Start Pacific Red Star
*Mtssa. Fitch 'lzum'
*Unlabled Intergeneric Oncidinae
*Unlabled Paphiopedilum

[Ray]

I am about 30 miles north of Philly, and I pull my shade cloth in mid-October, leaving all of the plants where they were. No issues whatsoever.

I really have to question your light readings, though. 6000 fc in mid-winter seems awfully high for your latitude, even at midday.

[Vanda lover]

During the winter, light is much less intense. Towards spring you have to be careful though. It seems to sneak up on you and suddenly they can be burned.

[jmoore3274]

I checked the light again. At 11:30am I'm getting max 3200 FC. Over the last month-month and a half the light intensity has really fallen off. I'm going to leave them where they are for now.

I was more worried about the cooler air on the lower level of the benches but I have not seen any ill effects yet. They seem to be fine. This is my first winter with this greenhouse so it is a learning experience.

Thanks for the help.

[Ray]

You should have fans running 24/7 in the greenhouse. It keeps the air buoyant and prevents such stratification.

[Masdyman]

I was going to say "6000FC" You lookinhg sod! That is summer for us!!!!!!!!!

[Optimist]

There is a greenhouse forum here with a lot of more senior orchid people who work with greenhouses regularly. I'll bet they can help you?

[WeirdGuySeattle]

I sort of have the same questions. The light drops below a bunch of trees so I get nothing but indirect light in winter. I don't think its close to 6000fc - probably more like 2000 midday - which is sort of perfect for me...

the short days are a problem though. I supplement with 2 LEDs (240W (i think) blackstar lamps). but this is pretty new. The plants have appreciated the extra light though. If you are getting 6000 during the day, I wouldn't worry too much. I am trying to get 11 hour days, and not all the plants are getting the supplemental light - my Cattelyas are just on the edge - I just rely on their food storage mechanism to get through the winter, same with my Cyms.

We'll see how my paphs / bulbos / pleuros do.