I have a female plant that went through the flowering cycle. I left a lot of flower material on the plant. I forced her back into a vegetative cycle. How many days should I keep her in vegetative before forcing her back into flower cycle again? How many times can I do this?

The plant can be forced to flower as soon as it has developed large enough new leads to support large buds. You may have to prune the plant, too, since revegetated plants have lots of branching. The plant can continue to switch cycles for a long time as long as it is not attacked by bacteria or a virus. One garden I know of was using the same plants for two years.