autoflowers are ruderalis, which means autoflower, the cross has nothing to do with how small they are. An auto sativa will be short because it flowers on age, not size or light. My 3 week old LR#2 are showing sex and about a foot tall. I will be crossing them with masterkush, widow and LT, havent tried crossing these before, but I understand the auto trait is in the males. LR#1 is shorter than #2, #2 was crossed with Haze to make it taller, but they still round off under 3 feet. Males grow taller than females, I give them vegging nutes until pistils or pollen sacs are present, than switch to flowering nutes. I have mine on an 18/6 schedule, but 20/4 is best for ruderalis. I use mh cause they are in my veg room. any questions pm me ..