Rhubarb is a favored perennial, valued for its tart stalks used in various culinary creations. Preparing these plants for colder months, known as winterizing, contributes to their long-term health and continued productivity. This process shields the plant from harsh environmental conditions, ensuring successful dormancy and a robust return in the subsequent growing season.
Why Winterize Rhubarb
Winterizing rhubarb offers several advantages for plant resilience and future yields. It protects the plant’s crown, where new growth originates, from damaging freezing and thawing cycles. This reduces root damage and helps deter pests and certain plant diseases. These steps contribute to vigorous growth and an abundant harvest in the following spring.
When to Winterize Rhubarb
The optimal time to winterize rhubarb is in late autumn, signaled by changes in the plant and its environment. Rhubarb leaves will start to yellow, brown, and die back naturally, indicating the plant is entering dormancy. Environmental cues, such as the first hard frost or consistently cold temperatures, also signify the appropriate period. While timing varies by region, these indicators provide a reliable guide.
How to Winterize Rhubarb
Preparing rhubarb for winter involves several practical steps focused on protecting the plant and its root system.
Cleanup
Begin by thoroughly cleaning the area immediately surrounding your rhubarb plant. Remove all dead or decaying foliage accumulated throughout the growing season. Using sharp, clean pruning shears, cut back any remaining yellowed or browned stalks and leaves right down to ground level, ensuring only the dormant crown remains visible. This clearing eliminates potential overwintering sites for pests like slugs or earwigs. It also significantly reduces fungal spores and disease pathogens that could infect new growth in spring, promoting healthier plant development.
Mulching
Following cleanup, apply a substantial, protective layer of organic mulch directly over the rhubarb crown and surrounding soil. Excellent choices include clean straw, finely shredded leaves, or well-decomposed compost. Distribute the material evenly, creating a 4 to 6-inch thick layer over the plant’s central crown. This insulating blanket stabilizes soil temperatures, shielding the shallow-rooted crown from freezing and thawing cycles that can heave plants out of the ground. Mulch also retains consistent soil moisture and suppresses weed growth.
Fertilizing
While heavy fertilization is not recommended in the fall, a judicious application of well-rotted compost benefits soil health. Before applying the mulch, spread a uniform 1 to 2-inch layer of this aged organic matter around the rhubarb plant’s base. This provides slow-release nutrients, improving soil structure and microbial activity as it breaks down over winter. Avoid using synthetic, high-nitrogen fertilizers during this period, as they can stimulate tender new growth susceptible to freezing damage. The main objective for fall care is to prepare the plant for dormancy and protection, not to encourage active growth.
Spring Preparations for Rhubarb
As winter recedes and the growing season approaches, preparing your rhubarb for spring emergence is straightforward. Once the danger of hard frosts has passed, typically in early spring, gently rake back and remove the thick layer of winter mulch. This allows the soil to warm more quickly, signaling to the plant that it is time to break dormancy. Look for small, reddish-pink shoots emerging from the crown, indicating new growth. Ensure the plant receives adequate moisture, especially if spring rains are sparse, to support its vigorous development.