Does LED lighting work for artificial plant light?

I am growing some herbal plants that require a delicate balance of lights and nutrients. Unfortunately it's not always sunny where I from, so I grow indoors. I setup a LED blue/red 255 tiny light system 12x12 inch over the small flat of rosemary/chives...etc. How close should it be and will it be effective? I want first hand experience.
Does LED lighting work for artificial plant light?
I start my plants (herbs, vegetables, etc.) every year in the house using plant lights, this year I switched to the "daylight" bulbs instead of the more pricey "plant and aquarium" bulbs, and they seem to be working just fine. The LED lighting won't work. I set my lamps about 8 inches above my seedlings and adjust as they grow.
Reply:no, not enough lumens. In other words to weak.
skates