You are fucked already. Its no longer in veg.
Start new plants on the side of it.
If i had to guess its either genetics or you just abused the hell out of them by overwatering.
And by that i mean little and often. Go large but let the soil dry in between.
Big roots=large plants.
@SilverDutchman, i noticed its your second grow of super lemon haze. Must be pretty good?
I upped my lamp to 20 hrs of light because it says will flower at 18 hours. Not a true auto?
This will fuck up my schedule for sure. But for the next 2-4 weeks well got at 20.