What is plant regeneration? Let's say you've grown some plants, your near the end of the flowering period, and your getting ready to harvest. You could take your fruits and flowers, cut everything down, and start over...but there is another option.
Your other option is to carefully harvest your produce and try to regenerate the plants. Any tissue above ground that is not a stem has the chance of growing when you try plant regeneration.
First, make sure you leave the plants with a little something besides stem. Any green leaf material or flower material you leave on will help. The more leaf you can leave on, the better the transition will be back into the vegetative state.
Next, water thoroughly. The water should have about 700 ppm of a well balanced all purpose fertilizer. Add to this 10 ml/gallon Thrive Alive B1. I sometimes use Maxsea 16-16-16, other times I use B.C. Nutrients. If you do not use a seaweed based fertilizer (like Maxsea), add 10 ml/gallon Maxicrop liquid seaweed. This will add micro-nutrients and some plant hormones.
After you've watered your plants well, change the light cycle back to
a vegetative light cycle (18 on, 6 off). Or, if you have a separate veg
area, simply return your plants to the veg area. This will begin plant
regeneration if there is any hope of it.
You will want to grow them vegetatively
until you begin to see vigorous growth appear, and at least a couple of
weeks after that. I shoot for four weeks of vegetative growth, which
cuts the normal time to to my next harvest in half. The more flowering sites (leaves and stems) you allow to grow out in the veg stage, the more successful and productive your flowering cycle will be.
Once you are satisfied with your progress, you can return the plants to the flowering stage light cycle and treat them as you normally would.
I would recommend you only regenerate the same plants once. Each time you try it, the plants are in a little worse shape and their soil ends up in worse shape than the time before. It becomes more and more difficult to overcome these negative factors, and at some point it becomes impossible to win this battle. It is better to preserve your quality, count your blessings, and chop 'm down once they've been regenerated once.