CactiGuide.com

Hey Cacti Folks,

So I built a new greenhouse out of twin wall polycarbonate, and I put 40% shade cloth over it. I've had my plants in for about 6 months. And of course, because it's growing season, I'm noticing some must not be getting enough light. My greenhouse gets excellent morning and noon sun, but due to a very tall tree, it gets spotty sun/shade from about 3pm onwards. I've purchased some 30% shade cloth to replace my 40% with, and am considering buying grow lights. Is that the right solution? If so, does anyone have any recommendations for lights? I've been reading other posts about LED vs. Fluorescent bulbs and feel a bit overwhelmed!

-Evelyn

Hi Evelyn,
I would go with NO shade cloth before considering artificial lighting. I think I would also look at tree trimming and/or greenhouse moving before artificial lights too. The light fixtures will probably block many times more light than they add.

Hey Daiv,

Ok, so I removed the shade cloth. Despite my efforts, a couple of cacti received sunburns (it was 115 degrees in Texas). Now everyone has adjusted. The front part of my GH gets a lot of sun, but the back of it gets mostly shade. And since it's winter and the sun is lower on the horizon, they're receiving even less light. It's weird too, bc some of my plants are completely fine- like my astrophytums, frailea, copiapoa, ariocarpus, most succulents, but others are stretching out (enchinopsis, rebutia, some mammillaria, and some euphorbia). Is that bc certain species can handle less light or aren't prone to etiolation, or is it their location in my GH?! Tree trimming would be difficult as these trees are old and tall. Also, I'm renting, so they're not my trees to trim. Moving the GH isn't really a good option either, but if I get really desperate I'll look into it. What are your thoughts about reflected light?!?! Do you have any other ideas?! Thanks!!

You'll have to get some fairly spectacular lighting to rival low-level sunlight or even outdoor shade over a whole greenhouse. Use all the natural light you've got first.