Plants getting too tall

Using a new grow tent and let my plants veg too long. Justed started flowering phase and plants are getting too tall. I can already see that in a week or so I will not be able to move the lights any higher.
Any suggestions? Would a mesh screen across the canopy help limit the height?

Mesh would help but top them at the 2nd node to create 4 heads that should make them bushy and smaller or top at the 1 real node to create 2 heads