Topping

Gmslave gave a great answer. I’ve already topped a month old seedling three times. Really you can do what you want with a photo period plant.

Theoretically every top make 2 mains. All depends how big you let her get. There's no telling how much. To many variables. Stress slows plants down. I opt for an extra grow in a year than to train and stress my girls. I know the extra harvest in a year gets me way more than topping my plants. With a perpetual grow, without any topping 6 crops a year is what I can put out indoors. That's way more weed I get, than topping the plants and only getting 4 grows in. Cheers