Rhubarb is a unique herbaceous perennial, botanically classified as a vegetable, yet often used culinarily like a fruit due to its tart flavor. The part consumed is the petiole, or leaf stalk, which ranges in color from crimson to light green. Many gardeners wonder if these edible stalks can be planted directly to generate a new plant. Understanding the plant’s biology reveals why this common assumption is incorrect and guides gardeners toward successful alternatives.
Why Rhubarb Stalks Cannot Grow New Plants
The edible rhubarb stalk is a petiole designed to support the large, triangular leaf blade. Plant structures like petioles lack the necessary meristematic tissue, which is responsible for cell division and forming new roots and shoots. When a harvested stalk is placed in soil, it cannot generate the new buds or root systems required for independent growth. The stalk will inevitably rot in the ground, as it is biologically incapable of regeneration.
A rhubarb plant must be propagated from its crown, which is the thick, underground rhizome where the plant stores energy and houses the dormant buds, or “eyes.” This crown is the true growing point of the plant. Propagation requires a piece of this root structure because it contains the regenerative tissue needed to form an entirely new, viable plant. The difference between the crown and the stalk is analogous to the difference between a tree trunk and a single fallen branch.
The Best Way to Start Rhubarb: Planting Crowns
The best method for establishing a rhubarb patch is by planting dormant crowns. Crowns should be sourced from a reputable supplier and planted either in early spring as soon as the soil is workable or in late autumn. Selecting an appropriate permanent location is important because rhubarb plants can remain productive for 10 to 15 years. Rhubarb prefers a site that receives full sun, though it can tolerate partial shade in hotter climates.
The soil must be rich and extremely well-drained, as crowns will rot if they sit in waterlogged conditions. The ideal soil pH is slightly acidic to neutral (6.0 to 7.0). Before planting, amend the area deeply with a generous amount of well-rotted compost or aged manure to provide the high organic matter and nutrients the plant needs. Rhubarb is a heavy feeder, and this initial soil preparation supports its long-term vigor.
When planting, prepare a hole large enough for the crown’s root system. The crown should be set so the buds, or “eyes,” are pointing upward, covered by one to two inches of soil. This shallow planting depth ensures the buds are close enough to the surface to emerge easily but remain protected. Space multiple crowns generously, allowing three to four feet between plants, which gives the large leaves room to spread.
After planting, water the area thoroughly to settle the soil around the roots and encourage establishment. Consistent moisture is necessary during the first year, but avoid overwatering. The most important rule for newly planted crowns is to prevent harvesting for the first two growing seasons. This two-year establishment period is essential to allow the plant to develop a strong root system capable of sustaining long-term, heavy production.
Growing Rhubarb from Seed
An alternative method for starting rhubarb is by planting seeds. Seeds can be started indoors eight to ten weeks before the last expected frost in spring, or they can be direct-sown into the garden bed. Soaking the seeds in warm water for a few hours prior to planting can help improve the germination rate. Seeds typically germinate within seven to fourteen days when soil temperatures are consistently between 68°F and 74°F.
A major difference in starting from seed is genetic variability, meaning the resulting plants may not be identical to the parent, and some may produce thin stalks. For this reason, gardeners must select the strongest seedlings and discard the weaker ones. Seedlings are then transplanted into their permanent location once they have their first true leaves and are large enough to handle.
The timeline for harvesting is longer when starting from seed compared to crowns. While crowns can usually be lightly harvested in their second year, seed-grown rhubarb often requires three years before the plant is mature enough to support harvesting without compromising its health. This extended waiting period ensures the root system is fully developed and the plant has stored sufficient energy.