This winter’s frigid temperatures may have kept you indoors, but your garden can’t escape the cold. Plant damage like winter burn or frost injury are common this time of year, and the dry weather the St. Louis region has seen in recent months adds to the chance of problems, but there are a few steps you can take to lessen the blow of common winter plant damage.
Winter burn is a problem for evergreens when dealing with low soil moisture, freezing temperatures and blowing wind. The condition causes plants to lose moisture faster than their roots can replace it. Conifers affected will show yellowish, or red, needle tips. Broad-leaf evergreens, like rhododendron, show browning of leaf margins.
Blocking the wind is a key way to reduce the risk of damage to plants. You can use simple devices like a burlap barrier, or a section of bamboo screening. To reduce moisture loss, put mulch around the plant. Watering is also important, especially since there area has had little precipitation since late summer.
When the ground thaws, give evergreens a good soaking intermittently until a normal rainfall pattern returns.
Frost injury and ice damage are also possible risks with frequently below-freezing temperatures. Damage starts with the softest tissue, like new leaves or tender shoots, and can cause plants to become limp and blackened.
Protection is essential to prevent frost injury. For container plants, sink them into the ground, heavily mulch them, or move them to protected areas. Cover tender plants with cloth or lightweight agricultural fabrics, not plastic, from top to soil to trap heat. Continue this practice into the spring until freeze warnings cease.
Pruning comes into play as well. While some plants, like ornamental grasses or summer flowering shrubs, can be pruned in mid-February to mid-March, you don’t want to prune everything at that time. For instance, if you prune spring blooming shrubs like azaleas or lilacs too early, you risk cutting off flower buds. Spring blooming shrubs are best pruned after flowering ends.
For more tips on weekly and monthly gardening tasks, check out Gardening by Month information on the Missouri Botanical Garden’s website.
Catherine Martin
Public Information Specialist
Feature image by Wesley Schaeffer