How long to veg

Hi wonder if anyone can help me I started a few months a go with a few seeds and only one survived and this is it in the picture, but was happy with the out come and only just recently brought a need batch of seeds and there doing great, how long should I veg for and what should i do

it's up to your hand. when you swich 12/12 they will duble some strains triple size. how much area you have? and take some pic normal light we can see easly

I have a 4ft by 4ft by 7ft tall, I did cut a lot of leafs off because it was getting big and wasn't getting much light to the bottom, when the best time to start flowering and didn't know they double or triple in size when they go into flowering, can't wait to start flowering ! Cheers for the message

note for that, do not put those thermometer in the ground. raise it up to your top of leaf level, you need to mesure hottest point of your garden. do you have probe?