Over wintering strawberry plants is the single most important cultural practice for ensuring a robust and productive garden the following season. While it may seem counterintuitive to protect plants during the cold months, this period is critical for the crown and root system to establish strength. Without proper care, strawberries can suffer from frost heave, disease, or desiccation, leading to weak growth and poor fruit yield when spring arrives.
Understanding the Strawberry Growth Cycle
To effectively over winter strawberry plants, you must first understand their perennial nature. Though often grown as annuals in some climates, these plants enter a state of dormancy when temperatures drop. During this dormant phase, the plant focuses energy on the crown rather than foliage, preparing for a surge of growth in the spring. The goal of winterization is to protect this crown, which houses the growing point for next year’s shoots.
Preparing Plants for Winter Cold
Preparation begins in the late summer or early fall, well before the first frost. This involves reducing nitrogen fertilizer to discourage tender new growth that would be vulnerable to cold. Additionally, ensuring the plants receive adequate water until the ground freezes is essential for hydration. Healthy, well-hydrated plants have a higher survival rate and are better equipped to survive temperature fluctuations.
Timing is Everything
The ideal time to prepare strawberries for winter is after the first light frost has blackened the leaves but before the ground hardens. At this stage, the plant has begun to slow its metabolic processes, making it less susceptible to shock. Applying mulch too early can actually trap heat and prevent the plant from acclimating properly, so patience is key.
The Mulching Process
Applying a protective layer of mulch is the most crucial step in the over wintering process. This layer acts as insulation, stabilizing the soil temperature and preventing the destructive cycle of freezing and thawing. Materials such as straw, shredded leaves, or pine needles are ideal because they are loose enough to allow air circulation while providing significant thermal protection.
Spread a layer of mulch approximately 4 to 6 inches thick over the entire bed.
Ensure the mulch does not touch the crown of the plant directly, as this can cause rot.
Apply the mulch after the soil has frozen to prevent rodents from nesting.
Remove the mulch gradually in the spring as new growth appears to prevent smothering.
Managing Snow Cover
Natural snow can be a valuable ally if it arrives after the mulch is applied. Snow acts as an additional insulating blanket, protecting the plants from extreme temperature swings. However, if snow arrives before mulching, it is best to leave it alone, as walking on wet snow can compact and damage the plants. The aim is to maintain a consistent, cold, and stable environment rather than to keep the plants warm.
Preventing Heave and Rodent Damage
Frost heave occurs when the repeated freezing and thawing of soil pushes plants partially out of the ground, exposing the crown to lethal cold. A thick mulch layer is the primary defense against this. Regarding pests, voles and mice often nest under mulch for warmth and eat the bark of the plants. To deter them, avoid piling mulch against the stems and consider setting traps or using wire mesh barriers around the garden beds.
Spring Awakening
As the danger of severe frost passes in the spring, it is time to reveal the plants. Remove the mulch layer slowly, ideally on a cloudy day or when temperatures are expected to remain mild. This gradual exposure prevents shock to the tender shoots. Once uncovered, inspect the crowns for signs of disease or pests, and water the bed thoroughly to encourage healthy growth.
By following these steps, you transform your garden from a seasonal display into a permanent, reliable source of fruit. Investing effort in over wintering strawberry plants ensures that the labor of spring and summer is rewarded with a bountiful harvest year after year.
