DogsNDaylilies said:
I wonder if its better to use white light and if that promotes more foliage growth which might help the plant strengthen and gain nutrients before it flowers. This is all coming from a new-to-indoor-growing person, so it's all speculation on my part.
...Is there anyone else who might know the answer or have a more educated guess?
Plants use visible light for photosynthesis roughly between 400 and 700 nanometers, but they use red and blue light more than they use of the other colours of the spectrum. They also use red light to measure the daylength (photoperiod) which is why incandescent bulbs are often used for daylength manipulation. ( Daylength is a bit of a misnomer really since plants actually are measuring the hours of darkness).
Anyway, from what I recall red light alone would make for plants that are tall and soft whereas blue light alone produces shorter "hard" plants. Commercial growers may manipulate the ratio of red to blue in order to control the growth of the plants.
Fluorescent lamps other than grow lamps emit mostly blue light but the cool white and warm white "regular" tubes are still fine for growing seedlings as long as they are emitting enough light intensity (this can tail off with age of the tubes and affect the plants making them "stretch" towards the light before our eyes can see the drop).
LEDs are appealing because of their low electricity use, whereas some other forms of plant lights are much more costly to operate. I've never used them personally though.
