I picked rhubarb until the first of July and then left it alone. it has come back more than the spring and wondering if i can cut it down again for another harvest, or is it late (august 15)? I would hate to see the beautiful red stems go to waste.
While it is possible to harvest the stems in August, harvesting too many will weaken the plant and lead to a smaller harvest next year. The stems won't go to waste in either case because the plant will store the energy for its use during the winter and next spring. See the following Q&A article for more: