Perennial vegetables need extra care to survive the harsh winter months, especially in regions with freezing temperatures. These plants, including asparagus, rhubarb, and Jerusalem artichokes, have long lifespans, producing harvests year after year. However, to ensure they make it through winter without damage, specific preparation steps are necessary. With the right care, these hardy perennials will emerge healthy in spring, ready to produce fresh, delicious crops for the growing season.
Asparagus Winter Care
Asparagus is a cold-hardy perennial that can survive in USDA hardiness zones as low as Zone 4, but it still benefits from a bit of extra attention in the fall. When the plant’s ferns start to turn yellow or brown—often following the first frost—it’s time to prepare for winter. First, cut the ferns back, leaving approximately two inches of stem above the soil. Trimming back these dead parts not only helps the plant focus its energy on root health during dormancy but also reduces the chance of disease setting in over the winter.
After cutting back the ferns, apply a layer of compost around the base of the asparagus plants. A two- to three-inch layer of nutrient-rich compost provides insulation and gradually enriches the soil as it decomposes. For added protection, cover the compost with a thick layer of mulch, such as rice straw, to a depth of around four to six inches. This layer acts as a blanket, shielding the roots from frost and temperature fluctuations. Come spring, remove the straw mulch once the risk of frost has passed, allowing the asparagus to begin growing again.
Rhubarb Winter Preparation
Rhubarb is another hardy perennial, known for its tart, edible stalks. Unlike asparagus, rhubarb requires minimal preparation to endure winter cold. After the first frost, or once the plant's leaves naturally wither and die back, cut the plant down to ground level. Removing the leaves and stalks in late fall prevents any potential disease from affecting the dormant roots.
Once the plant is trimmed back, cover the rhubarb crown with a four- to six-inch layer of compost. This compost layer will serve as both insulation and a source of nutrients for the roots. As it breaks down over winter, it enriches the soil, promoting strong growth in spring. In regions with severe winter weather, you can add an additional layer of straw or leaf mulch on top for extra insulation, although this is generally not necessary for rhubarb in milder climates.
Jerusalem Artichokes: Storing for Winter
Jerusalem artichokes, also known as sunchokes, are a unique perennial vegetable grown for their edible tubers. These tubers can be left in the ground throughout the winter and harvested as needed, provided that the ground does not freeze solid. In areas with mild winters, this approach works well, allowing you to dig up fresh tubers as desired.
However, in regions where the soil freezes deeply, leaving Jerusalem artichokes in the ground is not practical. Instead, dig up any remaining tubers before the ground freezes. Store these tubers in a cool, moist environment—such as a bin of slightly damp sand or soil—in a location that stays above freezing but below 40°F, like a garage or a shed. This method of storage mimics the natural conditions in which the tubers thrive, preserving them for later use without risking damage from frost.
By following these steps, you can help your perennial vegetables withstand winter’s challenges and ensure a strong start in spring. Proper preparation not only protects these valuable crops but also enriches the soil and promotes healthy growth for the season ahead.
To care for artichokes, check out our related article on Caring for Artichokes for more detail.
