"The Stretch" before & during beginning of flowering?

So I'm at my first grow season and I've been reading about many growers that talk about a huge stretch that doubles their plants size during the first stages of flowering around early-mid August.. My main concern is if I have multiple plants that are already 8 feet tall as of today would I absolutely need to find a 10ft stake so they don't fall over while putting on weight of big buds....? all of the main stalks are big and sturdy so any input about how much bigger people's plants got in the beginning stages of flowering would be much appreciated!

Alot depends on the strain. I run white widow that stretches about a third of the plant. On the other hand i've run purple kush that only stretches 6 inches or so.

Only my true sativas stretched a dramatic amount. I would support them up also. I use bamboo or smooth branches.