How deep should rhubarb crowns be planted?

To get started on how to grow rhubarb, it all begins with the placement of the crown. Buds should be 2 inches deep (below the soil surface), deep enough to insulate it from frost, but shallow enough to prevent raising the crown too high. I have found buried crowns in Colorado gardens that were planted too deep, preventing them from sprouting up to a couple of weeks later.

Rhubarb grows horizontally from its roots, requiring three feet between plants. When planted closer together, plants compete for nutrients. A client in Nebraska planted rhubarb in 18 inches spacing and the stalks were no thicker than a pencil. It's important to loosen the soil in both the lateral and vertical planes, which encourages healthy roots. With clay soils, you can also add gypsum into the soil to improve the soil texture.

The ability to drain will determine whether the crowns remain alive. In ponding (soggy) areas, I always line the planting holes with gravel, a helpful technique I learned from growers in Scotland. To do a drainage test, fill a 12-inch hole with water, and if it is still there after 4 hours, plan on raising your beds or looking for a better-sloped location to plant.

Fall planting is appropriate for planting in zones 3-6, giving time for roots to get established before frost. In zones 7 and above where winters are milder you can plant in the spring. A gardener friend from Vermont that I mentor swears by a September planting, and many of her crowns come up hardier in zones that see winters of -20 F. Mulch heavily when you plant.

Read the full article: How to Grow Rhubarb: Expert Tips for Success