Rhubarb is typically in season May through June. This can vary slightly depending on the planting zone you live in. Hothouse rhubarb may be available year round, but doesn't have as robust a flavor as seasonal rhubarb. P.S. That's right now, my friend! Make all the rhubarb things, right now! lol For instance, this delicious Rhubarb Dump Cake over at Little House, Big Alaska is a stunningly simple and delicious dessert! Give it a try, too!