Can Burlap Plant Covers Be Left on During the Day?

Time Frame

• Burlap may be used as a temporary plant cover from fall to spring to shield tender plants from cold. Do not place burlap over actively growing plants when the sun is shining and temperatures are warm because the burlap can limit light for photosynthesis or trap air and cause the plant to experience warm, stuffy air. Plants need carbon dioxide and expel oxygen during respiration; do not block this gas exchange from spring to fall. Burlap wrapped and secured over plants in winter, when the plants are dormant, does not need to be removed during the day.

Benefits

• Wrapping a dormant plant with burlap helps shield the leaves or twigs from drying cold wind and warming, drying sun rays in winter. Evergreen plants, whether with needles or broad-leaves, benefit from the burlap covering because air and light reaches the plant but temperatures and humidity are moderated under the burlap covering. When the soil is frozen, roots do not uptake water and transport it to the twigs and stems. Dry winds and direct sunlight can dehydrate twigs and foliage, causing leaf scalding and death. The burlap reduces the air flow across foliage and shades the sun, preventing water loss from plant tissues.

Removal

• It's important to remove burlap from plants once the coldest part of winter passes. This timing varies by region. Covering a rhododendron or cypress in Alabama is needed only in January and early February, but in Minnesota, the burlap covering provides protection from late November to late March. Once daytime temperatures consistently get above 50 degrees Fahrenheit in late winter or early spring, burlap wraps and coverings should be removed. Leaving burlap on too late prevents the warming of soil and plant tissues, prolonging their dormancy and potentially disrupting their natural biorhythms.

Summer Use

• Burlap may be a convenient plant cover to use in summer to protect plants from chemical spray drift, flying insects, foraging animals or scalding afternoon sunshine. Whatever reason burlap covers are used, remove them during the day, especially in the morning hours, to allow photosynthesis to occur. Covering actively growing plants is problematic because it may limit pollinating insects from reaching flowers, snap weak stems or shoots, or slow the drying of leaves and lead to fungal diseases. If heat and sun scalding is occurring in summer, only shade the plant during the heat of the afternoon to cool it, but remove it before dusk.