- Sat Oct 16, 2021 7:01 pm
As I prepare to skip dormancy on some of my plants and over winter them inside, I am noticing that many plants indoors has really colored up. The same plants that were green all season has suddenly colored up really well inside under LEDs in just a few weeks. I brought all the plants late summer and most have not even began to color up for fall. They only started coloring up very intensely under the LEDs. I read it all the time when someone asks how to get VFTs to color up, numerous people give advice of getting them as much sunlight as possible but I don't think that's the only thing that matters here. I'm not gonna pretend and say the lights I'm using can compete with the sun... it can't, but there certainly is something else at play and I'm thinking maybe the lower temperatures indoors. I'm also thinking that since most lights have a heavy red spectrum, even those that look white, maybe it's the reason the plants turn red to reflect away some of that excess red wavelength. My lights are rated at 4000 Kelvin. I'm only giving the plants around 20 watts per sq ft (around 500 PPFD at the center and 250 at the corners). The fixtures can get much higher than that but it seems unnecessary based on the growth and coloration that I have observed so far.
Does anyone have any feedback regarding this or have observed the same thing? I'm also wondering if someone has gotten better coloration when a shade cloth was used compared to full on sun.
I do know that in my location, direct sunlight is around 35F to 50F hotter than ambient temperatures. So my plants are actually experiencing closer to 140F under direct full sunlight on those 90F+ summer days here in zone 7B.
Here are some examples of plants that were mostly green before I brought them inside.
FTS Purple Ambush