It is not easy to get a pretty picture of rhubarb, Rheum rhabarbarum. The big and sometimes flabby leaves are only impressive to those who know about the succulent petioles (leaf stalks) below. The petioles do not look like much either, until they are cooked into pies or garnet colored preserves. Shabby stalks of tiny flowers rarely bloom, and should get cut out to favor more foliar growth.
Traditional rhubarb stalks are mostly green with a red blush, and a distinctively tart flavor. Some modern varieties with richer red color are not quite as vigorous, and have milder flavor. Varieties with light green petioles are probably the most productive, but are not so richly colored when cooked. Tender young stalks are preferred to firmer mature stalks. Leaves are toxic, so they are not eaten.
Petioles can be harvested as soon as they are big enough in late spring, and as late as autumn. The outer leaves get plucked first, which leaves smaller inner leaves to continue growing. Plucking most of the leaves gets more of the tender inner stalks, but also slows growth so that new stalks may not be ready for a few months. Rhubarb likes rich soil, sunny exposure, and plenty of water.