Plant rhubarb crowns between November and March, avoiding frozen ground. Choose a spacious part of the garden in full sun or semi-shade. Rhubarb does best in fertile, well-drained soil with plenty of organic matter. Add well-rotted horse manure around the base of your plants every year in early spring to boost growth. Harvest rhubarb stems by pulling and twisting the stems sharply from the base of the plant between March and July. Never harvest more than half of the total leaves on the plant. To allow the crown to establish, resist harvesting your rhubarb until the second year after planting.