Rhubarb originates from western China and the Himalayas, and its initial use was medicinal. The freshness and tartness of rhubarb make it a natural for all sorts of desserts (and savory dishes and drinks, too). Outdoor-grown rhubarb comes into season in March and April and carries on throughout the summer. Its vibrant red-pink hue adds an extra dimension to cakes, tarts, trifles, roulades, and pickles.