cut the upper 1/3rd of the plant off, and leave a few of the smaller buds and flowers on the bottom of the plant and place the whole plant back on 24/7 light cycle. I think this is what you're supposed to do anyway.
Yes if you leave some leaves and shoots on the plant it can be re-vegged on either 24/7 or 18/6. You can probably do this about 2-4 times before the plant will be finished.
I once regenerated a plant that had been harvested and only about 10 or 15% of it ramained. I just left some of the smaller buds on the bottom and turned it back to 24/7. It took a while before eventually some strange looking twisty leaves started to slowly grow out of the tip of the buds, (as I recall), but eventually the growth returned to normal and I was able to take some cuttings. For the first few weeks there was hardly any growth, but after the plant recovered it took off fast because it already had an extensive root structure and a number of leaves, unlike seedlings. I don't think I tried to re-flower the original. It was years ago, but I think it may have taken three weeks or a month before I was able to take some cuttings... (not sure exactly), but it takes that long to start over from seeds and there were lots of nice branches to take cuttings from. I'm NOT speaking from experience when I suggest that if you try to reflower the same plant, you'll probably want to either cut back the roots a bit and re-pot the plant or transplant it to a larger pot after the normal groth pattern picks up steam again. That's assuming you're growing in dirt.
thanks. this is my first grow i started with 96 plants. i took the males and i have 70 plants females from seeds. the seeds i got from friends and im on flowering stage 4th week i would like to keep the best plants as mothers so i have god shit all the time
two weeks ago i harvested my first grow. i cut all but two tiny buds off my plant and left the stalk,the two buds about the size of a dime and two leaves that were starting to yellow. i put the plant on 24/0 light and gave it nutes high in nitrogen. (mg for tomatoes) the leaves are coming on like crazy. at first they were single and smooth edged but now they're starting to look like mj leaves. my plan is to veg them until i can take clones. i'd say the main things to remember are lights and ferts. good luck. btw i harvested the two little buds today.lol