Green house question

iann · Post by **iann** » Wed Apr 15, 2009 3:32 pm

Polycarbonate allows a considerable amount of UV through, much more than normal glass, but this causes the plastic to turn yellow. Therefore polycarbonate sheeting is almost always coated to prevent any UV at all from reaching the interior of the plastic and hence the interior of the greenhouse. The cutoff of this coating is such that blue and very near UV transmission is better than standard "green" soda glass, but then cuts off all UV beyond about 350nm (off the top of my head). Glass UV transmission rolls off more gradually from about 380nm to 320nm, so not a massive difference really. 320nm is generally considered to be the start of UVB which is primarily responsible for giving you a tan and producing vitamin D.

Post by **CoronaCactus** » Wed Apr 15, 2009 5:03 pm

Duh...now i feel stupid

The poly panels i have are UV coated...

peterb · Post by **peterb** » Wed Apr 15, 2009 6:29 pm

well, you live and learn. I have wondered how greenhouse grown plants then get such tight, dense spines and so much wool...?

peterb

iann · Post by **iann** » Wed Apr 15, 2009 6:37 pm

Have you ever seen a plant spined like this grown in a greenhouse

Post by **daiv** » Wed Apr 15, 2009 6:57 pm

Which one? I suppose all of them! Just crazy.

Here is my favorite cultivation vs. habitat contrast:

http://www.cactiguide.com/cactus/?genus ... ies=aurata

iann · Post by **iann** » Wed Apr 15, 2009 7:22 pm

There's a cactus in there somewhere!

dustin0352 · Post by **dustin0352** » Wed Apr 15, 2009 11:35 pm

Wow thanks for all the info. I suppose the green house will help me find a home for plants that I have triple of. Maybe even a good spot for seed growing?? Since there is minimal amount of direct sunlight.

Cutting down the trees is a dream of mine. If we do decide to buy the house we rent then down they come!! I could take em down now as the land lord is cool as heck. (my pops). To take down trees here in florida is a pain....Anything over 4 inches in diameter requires you to buy a permit from the county. So you end up paying Joe Shmoes tree service 100 bucks a tree then 150-400 bucks a permit. Mind you each tree needs a permit. So with that said I should just move to Cal. or AZ!!!