How to Overwinter Rhubarb

Rhubarb flourishes in colder environments and can endure severe winters if properly maintained.

Regular observation throughout winter is essential to detect any issues promptly.

Taking off winter mulch in early spring promotes rapid new growth.

Understanding Rhubarb Overwintering

What Does It Mean to Overwinter Rhubarb?

Overwintering Rhubarb involves preparing the plant to endure the cold winter months. Since Rhubarb is a robust perennial, it naturally tolerates low temperatures but greatly benefits from some pre-winter attention. The objective is to ensure the plant's root system remains healthy and ready for vigorous growth in spring. This process includes several key actions, such as soil preparation, mulching, and pruning, all aimed at safeguarding the plant from harsh weather conditions.

Preparing Rhubarb for Winter

Preparation Schedule

Start preparing your Rhubarb for winter in the autumn, typically from late September to early October, depending on your local climate. The crucial point is to begin before the first severe frost. Early preparation allows the plant to gradually adjust to colder conditions.

Soil Conditioning and Enhancements

Proper soil conditioning is vital for your Rhubarb's health throughout winter. Ensure the soil drains well to prevent water from freezing around the roots. Incorporating organic matter, such as compost, can enhance soil structure and fertility. Applying a layer of compost (approximately 5-8 centimeters or 2-3 inches) helps retain moisture and supplies nutrients.

Trimming and Cutting Back

Cutting back Rhubarb leaves to about 7-10 centimeters (3-4 inches) above the plant's crown is essential. This prevents the leaves from decaying and forming mold at the base, which could harm the plant. Use clean, sharp pruners for precise cuts, and remove any dead or diseased foliage.

Protecting Rhubarb from Extreme Cold

Mulching Strategies

Mulching is a critical step in safeguarding your Rhubarb plants from intense cold. Apply a thick layer (around 10-15 centimeters or 4-6 inches) of organic mulch, such as straw, leaves, or wood chips, around the plant's base. This layer acts as an insulating barrier, keeping the roots warm and protected from frost heave.

Utilizing Row Covers or Cloches

For enhanced protection, consider using row covers or cloches over your Rhubarb plants. These can provide an additional shield against the elements, protecting the plant from wind chill and extreme temperature fluctuations. Ensure that the covers are firmly secured to prevent them from being blown away during winter storms.

Spring Care for Rhubarb Post-Winter

Removing Winter Mulch

As temperatures begin to rise in early spring, gradually remove the winter mulch. This action helps to awaken the plant and allows the soil to warm up more quickly. Be careful, removing the mulch too soon can expose the plant to late frosts.

Early Spring Fertilization

To give your Rhubarb a head start, apply a balanced slow-release fertilizer as soon as you observe new growth. This application helps replenish nutrients the plant requires for robust growth. A balanced fertilizer like 10-10-10 (NPK) is generally adequate.

Inspecting for New Growth

Regularly check your Rhubarb for indications of new growth. Healthy, vibrant shoots signify that your overwintering efforts have been successful. If new growth appears sluggish, ensure the plant has sufficient water and consider providing a gentle boost with a diluted, balanced fertilizer.