You just need to have the lights quite close to the tops of the plants. Depending on what light you're using, but with floros you can get them real close to the tops. If you're using a HID then you need to be a bit more careful cos you don't wanna burn them (like I recently found out) - was just thinking you could be growing outdoors, so if you are then ignore the above

BTW I like your avatar & name - 1 of my favourite animes