Shade Cloth Question

[mjff]

I want to cover my greenhouse with some shade cloth to cut down on the heat in summer. I was going to get the red shade cloth, but what % shade should I get?

The greenhouse is 30' x 60' and has evaporative cooling. I will be growing mostly palms that grow in full sun (Washingtonia, Butia, Butia hybrids, Sabals, Braheas, Jubaeas, etc.), should I put shade cloth on it at all?

[BS Man about Palms]

50% shade is good to grow pretty things that need some acclimation

30% helps the plant, and needs little acclimation..

most home stores sell 70%, best to shade people

[Pedro 65]

Martin, Red shadecloth is used in the flower industry. The Red spectrum speeds up photosynthesis and forces early flowering. Green and Blue shadecloth is the 1st preferred colour for large leafed plants (including Palms) then black. Black shadecloth shades the plants, whereas coloured cloths are designed for certain plants. People that like or want to grow broms under shade cloth for example use white or a very very light red brown shade cloth. The colours they acheive cannot be delivered by the run of the mill black and green. If you browse on the net you can see all the results of large trials in Middle east using different coloured cloths. They are very sun tough palms you are growing, if you do use cloth i personally wouldnt use anything above 30% for your mentioned palms. All the Best with whatever way you go. Pete

[ariscott]

I don't use anything more than 50% shadecloth.... anything more will make the plants grow weak, I think. Yes, they don't look perfect.... but at least when you plant them... they don't just shrivel up and die.... Just my experience...

Regards, Ari

[Rusty on Pine Is.]

This isn't rocket science.....the more shade a leaf gets as it is growing, the thinner and longer it will be..... which makes it less stable in a higher light environment.

...and Bill is correct, of course..... "Acclimation" to higher light intensity is more difficult when a plant is in increased shade during it's formative growth cycle.

Except that a leaf that is fully grown cannot adapt fully to an increased light level..it may be able to alter the hue to reflect the increased light,(it tends to turn red) but it is really the cell wall that determines its true light hardiness, and cellulose and lignin are not differentiating, so once formed the cell wall structure will not change.....

....so it is really only the newer leaves that 'adapt' to the highs light levels.

There is a shade cloth called Aluminet, that will keep the light levels high and reflect a lot of heat....i have seen it used with good results on other plants, and it was used specifically to reduce heat.

Rusty

[mjff]

Thanks for the information everybody. So far sounds like the 30% Aluminet might be the way to go as it will both keep heat out in the summer and reflect it back in during the winter, which was another concern I had.

[mjff]

I guess I should have mentioned that I don't plan on covering the entire greenhouse, just the side that gets hit by the sun in the afternoon, so the plants will have full sun in the morning and afternoon shade. I had them outside this summer and the plants that were in the sun in the afternoon did very poorly. I'm guessing because their pots got so hot. I bumped some up to bigger pots one afternoon and the soil in the pots was nearly too hot to touch! When I moved them to a spot where they got shade in the afternoon they started growing like crazy. Would that change your recommendation for a shade %?