This year I'm starting my grow light right away in the fall. It's a 400 watt metal-halide low bay light. If you've seen the thread with Steve's light, it's exactly like that only with a wider bell. I tried to get a picture:
It's hard to get a shot when the light is on, the camera always adjusts for the brightness, but you kinda get the point. I also made some big reflectors out of cardboard and white printer paper. I read that white paper reflects more light that foil, and diffuses the light so there aren't any hot spots that can burn leaves. I currently only have 3 plants under it right now- bambusa multiplex, pleioblastus viridistriatus, and japonica "akebonosuji":
They are on top of some plastic bins holding some water to raise the humidity a bit. I'm kindof lucky with the humidity thing, I don't have forced air so it doesn't get as dry here as it did in the apartment I lived at before I moved here. As you can see there is plenty of space on the ground for some more. Some internet sources say I should run the light 16-18 hours a day at a distance of only a couple feet from the plants, but last year with the light almost as high as the picture there I still had leaves burning. I suppose the tops of that japonica plant are only about 2 feet from the light, but 14 hours of light seems to be enough- all 3 plants have started taking off in the last couple weeks. the multiplex has accelerated in growth to the point that pretty much every single culm is putting out new leaves on all living branches, and new shoots have started even when the last couple haven't fully leaved out yet. These are more shade tolerant, so i'm assuming they don't need as much light as lettuce or something.
I have seen some leaf changes with plants under this light, though. My viridistriatus looks like this:
The new leaves and the leaves that grew when the plant was outside look like the traditional viridistriatus leaves with lime green and dark green stripes, but under this light they lose all of their lime green and become dark, almost like pl. pygmaeus, and they stay dark green when moved outdoors for the summer. Only new leaves that grow when the plant is outside look like normal viridistriatus leaves, until they go back under this light. Is it something to do with the spectrum or amount of light? I suspect they get less light under the sun because of all the shade in the backyard, but I also know metal halide lights have a different spectrum.
Some of the japonica "akebonosuji" leaves are still variegated:
Those 2 almost white leaves grew after I put the plant under this light, but other new leaves on taller, unvariegated culms are all green like normal japonica. Speaking of the non-variegated leaves, they got a weird blotchy look after being placed under the light:
I've seen this on other newly planted bamboos outside, but after the plant acclimated to the new location they went away.
The multiplex tends to get some weird patterns on the leaves, too:
It first arrived with a few leaves like that, and it grows that way on maybe a quarter of the leaves regardless of conditions. Here's a leaf forming like that:
Does anybody else's do that, or is it just mine?
Has anyone tried growing any tropical or at least warmer climate plants in cold climates using a grow light like this for winter? I guess bambusa multiplex counts, but that also seems to be a fairly common indoor bamboo and I'm looking for more of a challenge. Any suggestions? I've seen some cool looking tropical/less cold hardy plants that I wouldn't mind adding to my collection. Most of my plants need a winter hibernation so they are outdoors all year, and I figure since I can bring potted plants inside and put them under this light during the cold months I can try whatever I want. Some of the Chusqueas have some interesting characteristics, and someone on here had a post about growing Qiongzhuea tumidissinoda in a pot with plenty of light. Is something like that doable with this set up?
My other option is to focus on trying to get the Japonica as large as possible using this light. It's already adding leaves on all the culms and the rhysomes have reached the edge of the pot. It was a 1 gallon division I got about a month ago, and running the math the clay pot comes out to 5 gallons, so It should have plenty of root space for growth. Either plan is fine for me, I just like the idea of getting more plants because, well, I probably don't have to explain that
Also is there any way I should improve my set up? I've read oscillating fans help prevent limpness, but I'll have to secure the paper reflectors a bit first. Last winter the bamboos grown under this light didn't develop abnormally with no fans, but the vegetables did. I'm not going to start the vegetables for a few months, though, so I have some time to work that out.
