Growing Too Fast!

My 2 girls went into flowering 5 days ago. One was almost 2ft and the other 1 1/2 ft. Since then they have blasted inches a night. The 2ft is now almost 3 and the other is 2 1/2 ft. Is it too late too try and LST them? If not what's the easiest way to control. The ceiling in the closest is 8 ft so height wise it might be ok but IDK. The girls are starting too hit the sides though because it's a tight fit only about 2 ft from front to back. Any ideas?

I heard they can double or triple in size but this is crazy!!! In a good way I suppose.

i take it there sativa domonant cross plants if so you should have started at 12in. 8ft should be enough check your nutes as well maybe to much nitrogen it makes them spurt. nutes for bud n6/ph10/po20. good luck