Shade cloth %
 

New outdoor grow space in a new house.

I am in SE PA, and the area gets full sun from 10-11am until evening. I acclimate plants on their trek out from under lights with a week of full shade and gradually increasing from that.

I grow mostly higher light plants- cattleya alliance, catasetum, and dendrobium.

Any experience in this area of the US and what shade cloth % do you use?

I use Aluminet 50% now, then switch to 60% when it starts getting hot in the summer. It keeps the the greenhouse cooler that way. Outdoors you would probably do well with that range.

OK, let's say you're in Lancaster PA. You can go to First Rays' Natural Sunlight Intensity >> First Rays LLC , and you'd find that you'd get a max of 9800 footcandles of light intensity in the peak of summer (74 degrees).

If you're going for the 5000 FC max for catts, you'd want to block out 49% of the sunlight. So if you're going for a percent shade, I'd say go in the range of 40%-60%.

Another consideration in deciding between 50% and 60% is duration of direct sun. With full sun from 10-11 AM to sunset (through the heat of the day) I'd lean toward 60%. My California yard runs east-west, mostly unshaded, and so gets pretty much full blazing sun from fairly early morning to near sunset, and I use mostly 60% Aluminet(Paphs get 70%Aluminet, Cymbidiums get 45% "generic" shade cloth that just takes the edge off.)

monir derail, where do you guys get your alimunet cloth? i just have the Home Depot one

Two points-of-reference for you:

I used 30% Aluminet in Doylestown, but my greenhouse had a fair amount of shade from tall trees.

Parkside Orchids, whose hoop houses were out in direct sunlight, used 30% in the winter, adding a second layer of 30% in the summer. For the record, two layers of 30% results in a 51% reduction, not 60%. (70% of the light penetrates the top layer, and 70% of that penetrates the lower layer. 0.7 x 0.7 = 0.49 transmission)

Gothic Arch Greenhouses in Mobile AL will custom-make it to your specs and has the best price going.

sweet thanks!

I get it at shadeclothstore.com I have been very satisfied with their service.

Here comes the heretic (me):

I believe in giving the plants as high light as they can tolerate. Here in NJ (same latitude as you), I grow my Cymbidiums in full sunlight (zero shade cloth)!

If they go out before May 1st, I put them directly on the open benches. Later than that, and they go under shade cloth for 5-7 days, then into full sun. In order to tolerate the full sun, I also have to water them a lot. I give them 2 hours with a sprinkler, every 2-3 days (depending upon weather).

I treat my Laelia anceps and Dendrobium kingianum (and their hybrids) exactly the same way. They do just fine (and grow VERY well).

3 years ago, I included a couple of Laeliocattleyas by mistake. Both were 50% L. anceps, and both did far better in full sun, than they ever did in the greenhouse.

If you prefer to use shade cloth, I would recommend:
7-10 days under 50-60% (or in the shade of a tree).
Then use 30-35% shade cloth for the rest of the season.

NOTE: Plants grow as a function of light, water & fertilizer. If you increase one factor, you must increase the other two. In higher light, water & fertilize more frequently.

By the way, I just finished my new Vanda rack. They will be going out as soon as night time temps are consistently above 52-55F. They will start under shade cloth for a week, then they go into full sun also. However, for this group, I have to sprinkle twice daily (10 AM & 1:30 PM) for the plants to handle full sun.

Kim, i want to snuggle with that Vanda rack!!