Topped at 9 weeks--how much shorter will they be?

I’m a first time grower I’ve just topped my white widow feminized from seed that I started May 10 on Long Island, NY. The plants are in 30-gallon grow bags and range from 12-16" in height. They all appear very healthy. I fertilize with tomato fertilizer weekly (18-18-21, npk). I don’t over-water, but I always water when temps reach close to or over 90°. I was not interested in extensive training, but I don’t want monster heights either. If I just pruned the tiny little shoot at the top of each plant yesterday, what is the likely amount of height I’ve likely stunted? (A rough percentage is fine too.)

Welcome to the forum.

You will have better results with a proper cannabis fertilizer. Fox Farm’s Trio, Advanced Nutrients, and Jacks are all good brands.

None. Topping will produce a shorter plant, but will increase yields at the same time.

There is no fixed height to expect. She will get as tall as you let her grow (assuming a photoperiod plant.)

As far as stunting goes, topping can produce a pause in visible growth for a day or 2, but many plants truck right through a topping like it didn’t happen as long as they are healthy.

Keep in mind that cannabis stretches up to 200% in the first couple of weeks following the start of flowering. This is called the “stretch.” It’s not uncommon for cannabis to double in size during the stretch.

Welcome for a fellow long Islander Picture would help we have a lot of time left so they could get big I’m more of an indoor grower but do have a few plants outside every year but always seam to get eaten by some type of wildlife good luck and wellcome