Cfl bulbs can technically be put as close to the plant as possible without touching it, recommended distance is 2 inches, any further and the plant will reach for the light, i use 7 40 watt cfls to start my seedlings (40 real watts, not equivalent) so that brings me to another question, are you using a 300 watt equivalent cfl bulb? like the box would say something like, uses only20 watts but matches a 300 watt incandescent. so if its a 300 watt cfl of real watts and not equivalent, you should just move it closer to the plant, if it is a 300w equivalent, get more cfls and move them closer, good luck.