Rhubarb is a tart, versatile perennial vegetable that requires minimal maintenance once established. While many gardeners plant in the spring, fall planting is viable and often offers distinct advantages for the plant’s long-term health. Planting rhubarb crowns in the autumn allows the root system to settle into the soil and establish before the ground freezes. This timing prepares the plant for a robust emergence when warmer weather returns.
Why Fall is an Ideal Time for Planting Rhubarb
Planting rhubarb in the fall leverages the natural period of root growth that occurs when air temperatures cool but the soil remains relatively warm. This window, typically from mid-September until the ground freezes, allows the crown to establish a strong root system without the stress of supporting active leaf growth. The plant’s energy is directed toward subterranean development, anchoring it firmly before winter dormancy sets in.
The cooler soil temperatures of autumn reduce the risk of the young plant drying out, a common challenge with spring plantings facing immediate warming and sun exposure. Rhubarb thrives in regions with cold winters, requiring a prolonged period below 40°F (4°C) to break dormancy and stimulate vigorous stem production the following spring. Fall planting ensures the crown receives its full chilling requirement naturally, setting the stage for a strong start the next growing season.
Preparing the Planting Site and Crowns
Choosing a location that receives full sun is generally best for rhubarb, though it will tolerate partial shade. The site should remain undisturbed for many years. Rhubarb is a heavy feeder and requires rich, well-draining soil. The planting site should be deeply worked to a depth of at least two feet to accommodate the extensive root system. Incorporating a generous amount of organic matter, such as well-rotted compost or manure, improves drainage and provides necessary nutrients.
When planting the rhubarb crown—a piece of root with at least one or two growth buds, or “eyes”—do not bury it too deeply. Dig a hole large enough to easily spread the roots. Position the crown so the top of the buds sits just one to two inches below the soil surface. The crown should be covered with only a light layer of soil, which should then be gently firmed to eliminate air pockets. Space individual plants three to four feet apart, as rhubarb matures into a large clump.
Essential Care for Overwintering
After planting, provide immediate and consistent moisture to help the roots settle into their new home. Ensure the roots do not dry out while the plant is establishing before the onset of a hard freeze. Once the ground is frozen solid, apply a thick layer of organic mulch, such as straw or well-rotted manure, for winter protection.
This mulch layer, typically two to four inches deep, insulates the soil, helping to prevent the freeze-thaw cycles that can heave the newly planted crown out of the ground. It also enriches the soil as it breaks down, providing a slow release of nutrients for spring growth. Apply the mulch around the crown, rather than directly over it, to prevent moisture accumulation and potential rot.
Anticipating the First Harvest
Patience is required after fall planting, as the plant must dedicate its energy to building a strong root system to support years of future harvests. Avoid harvesting any stalks in the first spring after planting, allowing the plant to fully establish its vigor. In the second spring, a very light harvest of just a few stalks may be taken, but only if the plant appears robust.
By the third spring, the rhubarb crown should be fully established and ready for a normal harvest, which typically begins in early spring and lasts until the end of June. When harvesting, stalks should be pulled and twisted away from the base of the plant, rather than cut, to prevent leaving a stub susceptible to disease. To maintain the plant’s health, never remove more than about a third of the stalks at any one time, ensuring enough foliage remains.