I have grown white russian a few times and imo it prefers to be topped but you must top it no more than a week before you plant to go 12/12 as if you leave it any more it can end up a messy bush as i found out on my fist attemp at topping this strain the second time i topped it i flowered exactly seven days after topping and ended up with two extremely large colas/my preferance with this strain is 2 week veg then top then leave for 7 days then flower but that was down to my height restrictoins. this strain also loves scrog.hope this helps be safe the postman.