Lets discuss lower temps causing coloration?

Ive heard things about ways you can manipulate your buds to change colors like deep purple if you give them lower temps, is this true? If so is there any real benefit to doing this or is it mostly just for looks? I have a single, extremely healthy, beastly skywalker OG photo girl, who as of yesterday has been topped 7 times, once the main stem about 2-3 weeks ago, and yesterday i topped all 6 of the stronger nodes, i left the bottom two branches as im not sure if i will keep them or just trim them off the plant, theyre catching up, but very slowly and if theyre not as stong as the rest by flip in two weeks they will be taken off to conserve the energy. Im looking at atleast 12 mains now and a massive first ever harvest (fingers crossed). I want really pretty buds and love the purple color, what are thoughts? This plant seems to take stress really well. Currently week 5 of veg


I think there’s a certain gene for the purple coloration in plants. If yours have it I seen it in the fan and sugars leaves and also concentrated within the buds. To get that I’ve heard to have about 10-15f temperature difference between day and night. Also increase in the deep red right before lights out/on will help with converting sugars during the night.


That is gorgeous :heart_eyes: i hope my buds look that nice!

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Cooler lights out temps can cause blues and purples to show more in strains that have those genes. Some articles I’ve read suggest night temps as low as 50°. It’s purely cosmetic though. There won’t be any increase in potency. Sure does look cool though.

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Thanks @Sweenzzzz
Deeps reds just came on for the early morning stretch.

Now they’re up and running


I was wondering about this, wasnt sure if it was genetic or strictly environmental, guess i will have to wait and see! I got the 3x10 seed pack OG mix from ILGM i currently have 10 fire OG seeds, 9 OG kush (germed one and never planted) and 9 Skywalker OG feminized photo seeds and im regretting only planting one! But also glad i waited as this has been great for learning what i need and want to know! Id love to see photos of any grows you guys are working on! Im currently on day 34 since sprout in my first grow!


I think it is genetic more than temp dependent. I have frequently seen sister seedlings of pedigree purple strains be green at harvest and purple at harvest. Like sister1 (same seed pack) green and sister2 the purple people eater. This is outdoor with cold fall temps.

The rub is some of the seeds (sister3) with purple genotypes will express by temp only if cold. While sister2 was the purple people eater as soon as she had true leaves. Yet sister1 (more like dad) will stay green as cucumber no matter how long you leave her in the fridge.

Interestingly (sorry relevant tangent) I remember hearing an interview (old podcast sorry cannot remember enough to reference the episode) with DJ short talking about the purps. He said they were weaker back in the day compared to greener strains. The theory was that the anthocyanins (purple pigment in blueberries, raspberries, elderberries) were like an antifreeze in the plant. On the older strains the plant would put all the effort into anthocyanin production instead of cannabinoids. They would smell sweet like berries but be weaker. So a lot of effort was put into breeding stronger purple strains that would produce anthocyanin and cannabinoids at the same time.

Great thread. I found this topic interesting and relevant. I definitely remember sitting pondering if purple is cold dependent or not, or stronger. Either way it’s a pretty looking thing when there’s a touch of colors.

Here is a cross I made. I believe I crossed jillybean x island sweet skunk. These are sister seeds out of the same F1 beans.

Rodelized mom (pollen to jilly clone)



Here’s the one im working on currently or I guess more precisely waiting to work on. Been drying eight days. Be in trim hell, err, jail in the next day or two. Three GG4 autos. They went 101 days.

I know Skywalker OG has the potential to show blue. I’m sure you saw the pic on the ILGM website. I’ve never seen anything like that picture IRL.


Man these plants are just so fun to learn about! Its crazy to my how weve figured out so much about something that has such a wide diversity of genes, all the different factors and the tricks to manipulate the plant to grow the way we want it to, getting into this last november i had no idea there was so much! Im loving every second of it!


I got some kool colors going on this God Father OG strain. I think I got this intense colors from two things. I read somewhere that adding UVA to your grow also helps to pull out the colors. Seem to have worked on this strain.

  1. During mid flowering I set my temps at 72 high and 60 for the low when the lights were off.
  2. I added two “FGI 360nm to 400nm UV-A LED” grow lights with my 400w Ace Infinity…

This is mostly genetic and has to do with anthocyanins. If you have this then cooler temps can help express them more. But if not genetically present cooler temps not as helpful. I have read other ways of doing this as well, such as ph manipulation.