Is 30% light o.k.?

Do-it-yourself projects such as greenhouse or shadehouse builds and related topics.
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pokey1
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Location: Orlando, FL. Zone 9-A (and B)

Is 30% light o.k.?

Post by pokey1 »

Hi all... I am in the process of building a "mini-greenhouse" due to an expanding collection, and have a few questions if I may... The unit will be attached to the back of my house, will be about 10 inches deep, 40 inches wide, and 5 feet tall. Slanted plexiglass top, plexiglass door, sides, and shelves. It will sit about 3 inches away from the wall, with the back made from screen for air circulation. And bug proof! Due to limited space and positioning, the cacti will only get about 5 hours of direct sun in this, but what should the shading be? 30% seems to be the average I've found. I have a light meter to check. I am thinking of either shade cloth, tinting, or screen for shade. Any input would be really appreciated!! Thanks as always... Joseph
Proud papa to 25 Genus and 78 species of these prickly devils.
iann
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Re: Is 30% light o.k.?

Post by iann »

30% shade cloth? The standard convention is that it would block 30% of the light. This is considered only a low level of shading and you probably won't find anything lower. Should be fine, although there are certainly cacti will will grow well under heavier shading. 70% shadecloth (30% of the light hitting the plants) is pretty high, too high for desert cacti.

If the sun is only in the morning then you might not need shading at all. A wall already lowers the light level more than you'd think, although it might reflect a fair amount of extra heat onto the plants.
--ian
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oldcat61
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Re: Is 30% light o.k.?

Post by oldcat61 »

I would guess it depends on where you live - Florida sun would be stronger than England or the northeast. I have a 13 by 8 lean-to in NJ & by tucking the epis up against the roof overhang & using stacked shelves I've not needed shade cloth. Watch your plants carefully, acclimate them gradually & they should tell you what they need.
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CoronaCactus
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Re: Is 30% light o.k.?

Post by CoronaCactus »

I would advise against any kind of window tinting film as most film blocks out from 90 to 99% of the suns UV rays.
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BarryRice
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Re: Is 30% light o.k.?

Post by BarryRice »

Hi Joseph

I use window screen. Using a light meter, as accurately as I can, I think I am getting about 30% shading (70% transmission). My plants in California get burning hot sun all day long. The shade cloth seems sufficient for my diverse collection (nothing über-rare).
I'll grow it as long as it doesn't have glochids. Gaudy flowers a plus.
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