shade clothe percentage

[fbashplant]

Now that Spring has come to the Northern hemisphere and the sun is getting hot here in South Florida I'm thinking it's time to get some shade cloth to protect my Catts and Dendrobiums. I know they need quite a lot of light so would 75% cloth be suitable? That is what they stock in my local "big box" stores. I know I can get other percentages on line. What is the senior member opinion? My plants are outdoors on my patio in Stuart FL which is just North of Palm Beach, latitude N27* 12' for those techniclally inclined. This will be the first Summer that I will be involved in orchid growing so I have a lot to learn. Any advice is appreciated.

[Kmac]

I've never done that, but our our orchid society recently had a grower from Venezuela speak on catts. He uses 50% shadecloth for his catts, if that helps at all.

[cdayinflorida]

I use a combo of 40% and 60%. 40% for the Vandas and 60% for the catts. I found I would get scorched foliage on the catt/laelia types in south Florida when I used 50%.

[fbashplant]

Thanks Cathy. Sounds like 75% isn't giving my catts enough light. There is a garden center near by that sells 70%. I might be splitting hairs but I might go for that instead.

[fbashplant]

Thanks Kathi. I need all the info I can get. It was hot today. I'll have to attend to this soon.

[Dorsetman]

Or just leave some spaces between the several (?) pieces. As the sun moves across the sky, you get alternate sun and shaded sun _ which is very natural. Don't think you have to cover every inch of the glass or whatever. I usually leave the gable ends uncovered so that the evening sun streams in through clear glass, and gives final shot of light and warmth before sunset.

I often end up with several layers of cloth , too. So I am not concerned about whether it is 40, 50, or whatever nominal percentage.

[espranch]

Right now, I have a 40% on the greenhouse roof. That will change to 62% when the sun gets directly overhead by the third week in June. The heat is very intense during the Summer here in Texas. Betty

[georgeo]

Hi Fred,

Greetings from Australia.

In relation to Australia, you are similarly located to Brisbane Qld (Eastern Seaboard), close to water, pleasant sea breezes, but during summer very hot and humid.

Assumably you have access to the sun that is not blocked by buildings or trees, if so, for good flowering about 50% is optimal from say mid autumn to spring (or similar light on a bright overcast day), however, given your location the leaves will overheat during summer and increasing the shadecloth to 70%plus during the "summer period" should be considered (or look it at another way, this will offset the amount of light received because of light day length and intensity). You could initially try a permanent layer of 40% and a further layer of 40% during "summer period", if possible leave a gap between the layers.

The leaves will tell you whether you've got the mix right, they should be a medium green colour and pseudo bulbs/canes rigid and erect without staking.

I also run a fan during the summer period to ensure good air circulation, additionally ensure humidity remains high.

Basically use common sense, if you are comfortable in an enviroment so will the orchids, if not, change it.

Regards

George

[fbashplant]

Thanks George, The advice from you and Geoff and Betty and others has given me a pretty clear idea of what I should be doing. Thanks to all for the good advice/info it's much appreciated.

[Halloamey]

You have got very good advice from others, but I would like to add my two cents. I grow my orchids in a greenhouse year round in hot sunny conditions. Since my greenhouse is on a terrace with unobstructed sunlight, I use a 90% shade cloth (allowing just 10% light in). Light and temperature go hand in hand. Under low temperatures orchids can take more light whereas under hot conditions the same amount of light can burn them. In the cooler months I remove the shade cloth to allow direct light.