What type of shade cloth is best for my situation

[BrassavolaStars]

Hello All,

I am currently furnishing my greenhouse for my orchids and was wondering if anyone knew what shade cloth would be best for me.

I have Phals, Cattleya/Brassavola, Soft cane Dendrobiums, Paphs, and a few Angraecums.

The greenhouse is 6mm twin wall polycarbonate and it is situated in mostly sun (all day). The longest sides of the greenhouse face North and South and the West side sun is partly blocked by my house

I live in southern NY (only a few miles north from NYC). The max temp in summer is about 100F with high humidity (70-100%) and most of the summer is around 86-90F.

I have tried putting my phals in the greenhouse only to have them get badly burned so I definitely need something.

Would 70% shade be too much? This is the cloth I ordered but I could still easily return it.

PS: the plants will be very near to the walls.

[Ray]

You have listed plants that have quite a range on light intensity needs. "One size" (shade) does not fit all.

You have a few alternatives. One is to cover part of the greenhouse with one "weight", and another with a different one, grouping the plants under the appropriate ones.

A second is to cover the greenhouse completely with a lesser shade value (I'd think 30-40%, based upon my experience in SE PA), then suspend a second layer inside the greenhouse above the low-light plants. Or, if you have the vertical room, have the higher light plants be up high in the structure and the low-light plants low.

Also...get Aluminet from Gothic Arch Greenhouse. It will reduce the heat better than any other type of cloth, and they have the best price out there.

[IngieBee]

You can also build your benches one above another creating shade? Phals can't take much sun, and you do need to make sure it's not so hot inside. I live in a very hot climate and I just bought my first greenhouse, and I got the 70% aluminet brand because independent studies show that either this product or white netting are the only ones that actually cool the interior. But I have no real life experience yet

[BrassavolaStars]

Hello Ray,
Thank you so much for the info. The shade cloth that I may return is 70% aluminet. Would the 70% have any use for me at all? Should I just return this cloth as it would make it too shady for the bulk of my plants less maybe the paphs? I want to get a cloth value that will be a good baseline for the hot summer.

[Ray]

In southeastern PA, a local commercial greenhouse in full sun used 30% year round, adding a second 30% layer from April to October.

My greenhouse there, which was on a hillside and protected by some trees, had 30% in the summer.

Are there any nurseries near you? Call or visit them and ask what they do!

[camille1585]

Going on Ray's suggestions to contact local nurseries, J&L orchids is in the region (southwest CT) so they may be a good place to get information!

[Fairorchids]

Glass lets almost all light through, while plastic & twin wall polycarb absorb about 15%.

Also, shade cloth is usually rated with a number, which indicates how much of the full sunlight it blocks.

In this part of the US (NJ/NY/CT), I would normally provide:

0-20% shade for Cymbidiums, Laelia anceps, Australian Dendrobiums, reed stem Epidendrums & Vandas.

30-40% shade for Cattleyas, Oncidiums, Ascocentrum, Aerides, Rhynchostylis, Denbium phalaenopsis & Latouria Dendrobiums.

60% shade for Angraecums, Paphs, Phals & Sarcochilus.

So, if you have greenhouse cover that absorbs 15%, add 30% shade cloth = about 60% getting through.

Then add an internal layer of 30% shade cloth over the low light plants = about 40% getting through.

[WaterWitchin]

Nice compilation of list, Kim. I'm zone 6a, and I'm keeping this handy. I love it when a grower gives out info like this. Saves a lot of time when trying to figure out appropriate light range.

[Ray]

Originally Posted by WaterWitchin

Nice compilation of list, Kim. I'm zone 6a, and I'm keeping this handy. I love it when a grower gives out info like this. Saves a lot of time when trying to figure out appropriate light range.

Hang on now.... Your USDA zone has NOTHING to do with light levels. It's about minimum temperatures.

For example, my location and that of Seattle WA are in the same USDA plant hardiness zone, yet due to my latitude, I get a lot more light, so would need more shade for the same plants.

{EDITED BECAUSE WHAT I SAID PREVIOUSLY WAS TOTALLY WRONG!}

If you go to the University of Oregon Solar Radiation Monitoring Lab calculator and plug in your zip code and time zone, you can get a chart of your solar elevation levels.

The light intensity reduction with solar elevation is a sine function, not linear as a previously misstated and have since deleted.

[WaterWitchin]

Originally Posted by Ray

Hang on now.... Your USDA zone has NOTHING to do with light levels. It's about minimum temperatures.

.

Whoah!!! Well THAT's good to know... and thanks for the link. I'll check it out. Then likely need an interpretation.

PS So Zone is ONLY about temperature, and nothing else, right?

---------- Post added at 10:55 AM ---------- Previous post was at 10:40 AM ----------

Okay, this brings up another question. So let's say I'm zone 6a and purchasing a regular old perennial plant for my garden. Almost all purchasing sites give you zones where it will winter over. And also tells you the plant grows in full sun. So I get my plant, plant in full sun, and it can't handle full sun in MY particular part of zone 6a. (Been there, done that.) Am I now following what you're saying?

PS I downloaded my chart... now to see if I can figure out my math.