Substitute 2 bags (16 oz each) frozen unsweetened rhubarb, thawed and drained, for the fresh rhubarb.
Substitute 3 cups sliced fresh strawberries for 3 cups of the rhubarb. Use 2 cups sugar.
Rhubarb is very tart, so there’s a lot of sugar in this pie. Use the lower amount of sugar for young, thin rhubarb stalks.