and to elaborate on what urgod said:
300watt CFL = about 60 actual CFL wattage, around 3500 lumens(in 360 degrees around the plant), you want a focused minimum of 3000 lumens per square foot with penetration. 6" away with a cfl is asking for stretching, even with that high powered of a CFL. get it as close as possible without burning it, and reflect it down towards that plant as much as possible, keep it from stretching