When the plants have grown enough to begin fruiting or flowering, they need more light than before and they prefer a warmer light, i.e. light that contains more red.
In most cases, you will want to supplement the light you use during vegging with some additional bulbs. Personally, I just hang a few CFL bulbs (warm light) here and there to add some more output and really stimulate flower and bud production. If you are unsure how many CFLs you need, this article will help.
What Fluorescent Bulbs For Growing Flowering Plants (Marijuana, Tomatoes, Etc)?
If you’ve got a very small garden, CFL bulbs (pictured at the beginning of the article) make the most sense.
As mentioned above, when it comes to compact fluorescent lamps, I would not worry about getting a dedicated grow bulb. They cost a lot more, but are basically the same as a regular CFL bulb.
What Kind of Fluorescent Bulbs for Plants that Don’t Flower?
But it’s not quite so simple.
The light from an HPS appears yellow, and is great for flowering plants because the light spectrum stimulates bud production
HIDs are very well suited to growing cannabis and very easy to use once they’re set up. If your main goal is to get the highest yields possible, then HIDs are the way to go! However, they do require extra setup compared to the other grow lights because chances are you will need a fan to vent out heat from your grow space.
If you get very high-wattage LEDs, you may need to vent out heat to keep the grow space cool
Cons of Fluorescents
3 Main Classes of Marijuana Grow Lights
T5 Grow Lights
“LEC” and “CMH” both refer to Ceramic Metal Halide grow lights, which is a type of HID light that is a bit more efficient than a regular Metal Halide light
Metal Halide (MH) Grow Lights