When to cut lower growth?

So I've heard that cutting lower chutes and cause energy to be more focused on the bide sites getting more light, how far along the life cycle do you do this and why? Thanks for any useful info!

I lollipop when going into flower, as well as at 21 days

This really depends on the lights you are using

if using shit lights then I'd agree to trimming the lower shoots

as the light don't reach that far, that said its good to try making some clones too

so snip of those lower shoots that struggle to get light and clone them off

shit lights as defined as cfl's T5's/T8's and any led under $800.00

good luck

Thanks looks like I should get trimming!