I just harvested my 3 tall ass sativas,
Here is a rundown.
4x5x8' closet----totally ran out of space by half way tru the grow
3 sativa power skunk one each in a 5 gallon bucket
Veg for 4 weeks, went to flower they were 24" tall....at max height they went to 84" tall, thats 7 feet, notice that is 3.5 times as high, by harvest they were only 6 feet tall due to droopage of the heavy ass buds, but they did hit the celing for 3 or 4 weeks before they got to heavy to stand up.
Grown under 400w mh and flower under 400w hps. Also had an additional 4 85w cfl and 4 43w cfl's.
Used only the GH Flora series for nut's and at the last 2 months added some GH Kool Bloom. 2 to 4 weeks flush at the end.
Total dry harvest 22+ ounces
Oh also I strongly believe in using Hygrozyme to keep the roots healthy.
Oh and one more thing, you can't harvest by tric color on a sativa cause the tric's, or at least mine didn't, never turn milky or amber, they stayed clear to the end. I had to harvest cause the plants were 50% dead and any more time would have affected the harvest. However the bud's turned out fucking execlent!! Damn near the best weed I have ever had, and people love it.
I also noticed that when switching from grow to bloom nut's don't stop using a little grow nut's along with the bloom nut's, the directions may say otherwise but my plants needed extra nitrogen that the bloom nut's wern't giving them.
And yes, it took 22 full weeks from seed to harvest. But I got 22 dry ounces. Also IMHO you cannot make them grow any shorter by topping them a lot, when you do side branches will quickly resume the tall growth, I topped mine 3 to 4 times to no effect, just got more buds tho, which is good but it didn't effect how tall they got.