Shade cloth or shade screen? What %?

[mimigirl]

I am making a covered shelf to summer outside the few orchids I have. Some are high light, dend etc, some low light. I can move the shelf about to change their placement. The spot i have receives morning and early afternoon sun. Again I can move the shelf about. What per centage of blockage am i supposed to use? I live in new orleans in zone 9. Also which do you suggest shade adjusting screen or cloth? I hope i have explained myself well enough.

[Ray]

You really need to talk to local growers and learn from their experiences; it's much more reliable that any you'll get from folks from elsewhere.

Give the folks at Gothic Arch Greenhouses a call. They are in Mobile, so will have similar light levels, and they offer the best price for Aluminet.

As a general rule, early morning sun is not going to hurt anything. The stress occurs as you approach=, or pass noon.

[mimigirl]

Ray i appreciate your reply. Calling Gothic seems like the best step to take. I will post his advice in case anyone else has a similar question. Thank you!

[Raqsharqi]

I had my phals, oncidiums, an angraecum, a neostylis, a finetia falcata, a laelia anceps, and a dendrobium outside in the somewhat shaded area of a patio all summer, and other than the burn one oncidium got when one leaf strayed out of the shadows into a ray of sun, they all did well. The area gets morning light, and though it isn't covered by more than a bit of lattice, the shade was enough. The phals were pushed a bit towards their maximum tolerance for sun, and many of the reddish flowered plants got reddish leaves, but the roots grew like crazy and I got some good leaf growth as well. I'm in Tucson and the sun is darned bright! I have had them mostly under two layers of shade cloth (the generic stuff you'd find at a garden store) all winter, and will add the Aluminet towards the end of April.

[mimigirl]

The reason i want to cover them is protect from critters! I have a shady area but if I am going to cover them I may as well put them in a sunnier area, right? I would rather use the generic kind because i can see it before i buy it. What percent blockage do you use even though our areas are different?

[Raqsharqi]

The roll I have says "up to 70% shade". I'm taking that with a whole salt shaker of salt! I used one layer to protect my tomatoes from the summer sun, so I doubled that for my orchids in the greenhouse this fall and winter. I can see that unless I add more shade, the greenhouse will be too hot come late spring-summer, so I'm adding more. You have the advantage of humidity to help the plants deal with the heat; I have very little. The only critters that might be deterred are a few birds. I didn't find the shade cloth did anything to deter all the other creatures....not bugs, not squirrels, not the quail or doves that liked the shade as a place to nest.
When I had mine orchids outside, I was just using the eyeball test to see if the light was right. Once I got the greenhouse, I also got a meter. With the polycarb 10mm double walls of my greenhouse and two layers of the supposed 70% shadecloth, the oncidiums get a good 30,000 lux in their home near the southern facing window. The phals are lower, farther from the window, under the shade of some pepper plants, and they are probably at 10,000 lux...again, pushing the limit. My greenhouse is only 8x8, so I don't have a lot of wiggle room for shade, especially since half of the space is filled with veggies that like full sun.

[DrLego]

Calling local is always the best option.

From my experience, it's a lot easier to add a second layer of shade to reduce light levels than it is to, uh... modify your new shade to increase light levels.

[mimigirl]

That is true. I keep saying i can move the shelf for more shade but forgot that the shelf moves both ways, into more light. Maybe start with 50% blockage?

[AJW]

Shade is shade. critters are critters the only connection being some critters like the shade.
Before you jump into shade cloth have a look at the orchids you are growing and their needs. As mentioned by others local knowledge is a good starting point.
You may also find they have had a similar critter experience and can help. I tend to use a rule of thumb when it comes to shade that being "if I can pass my hand over the plant and not see a shadow then I have enough shade. Good on you for raising the topic.