The cultivated strawberry, a member of the Fragaria genus, is a perennial plant whose foliage behavior is highly dependent on local climate conditions. Therefore, strawberries are often classified as semi-evergreen or semi-deciduous, reflecting their flexible growth habit. Their low-growing structure, which consists of a central crown and a whorl of leaves, is specifically adapted to survive a range of temperatures from mild winters to deep freezes. This perennial nature means the plant itself lives for multiple seasons, even if the leaves do not.
Defining Evergreen and Deciduous Plants
Plants are generally categorized by the way they manage their foliage across seasonal changes. Evergreen plants retain a portion of their green leaves throughout the entire year, with leaf drop occurring gradually over time rather than all at once. Deciduous plants are those that shed all of their leaves seasonally, typically in the autumn, as a survival mechanism to conserve water and energy during cold or dry periods. The lack of leaves reduces water loss through transpiration when the ground is frozen or water is scarce. The term semi-evergreen is a descriptor for plants that fall between these two extremes, holding onto their leaves in mild conditions but shedding them during harsh winters or periods of extended drought.
Strawberry Foliage Behavior by Climate
In mild climates, where temperatures rarely drop below freezing, strawberries act much like true evergreens, keeping a substantial canopy of green leaves throughout the winter months. They continue to photosynthesize slowly, utilizing available sunlight and moderate temperatures. Conversely, in colder temperate zones that experience hard freezes, strawberries exhibit a more deciduous behavior. The leaves turn reddish or brown, die back significantly, and may collapse to the ground after prolonged exposure to temperatures in the low 20s or teens Fahrenheit. This leaf dieback signals the plant is entering winter dormancy, a process initiated by declining non-freezing temperatures in the fall.
Seasonal Leaf Renewal and Crown Protection
Individual strawberry leaves have a finite lifespan, with a typical turnover period of about one to three months. Even when the plant appears fully green, the plant constantly replaces older, outer leaves with new ones emerging from the central growing point. This perpetual renewal process ensures the plant maintains a functional, photosynthesizing canopy under favorable conditions. During the winter, the primary function of the foliage shifts to physical protection of the crown, which contains the plant’s growing point and future flower buds. The older leaves that die back create a natural insulating layer over the crown, crucial because the unprotected crown can be injured below approximately 15°F.
Practical Implications for Cultivation
Crown Protection
The semi-evergreen nature of strawberries has direct implications for how they are managed in cultivation, particularly in regions with cold winters. Gardeners must ensure the central crown is adequately protected from freezing temperatures, as most unprotected varieties risk injury below 15°F. Applying a thick layer of loose mulch, typically four to six inches of clean straw, is a common practice after the plants have gone dormant and the soil has frozen slightly in late autumn.
Renovation
The characteristic of leaf renewal informs the practice of “renovation” for June-bearing varieties after harvest. This involves mowing or cutting back the old leaves to about two inches above the crowns. This defoliation encourages a flush of new, healthy leaf growth in late summer, developing a robust leaf canopy before winter sets in. This new growth helps insulate the crown and is correlated with a higher yield in the following spring.