Above photo by John E. Woodmansee
I don’t know about you, but the older I get, the less I like snow. But, from a gardening standpoint, should we hope for snow?
The answer to that question will vary from gardener to gardener. Generally, though, snow can be good for landscape and garden plants (to a point), especially if temperatures get unusually cold.
Rosie Lerner, Purdue consumer horticulture specialist (now retired), wrote that snow provides moisture as well as protection from cold and wind.
“Snow is an excellent insulator against low temperatures and excessive winds,” she said. “The extent of protection depends on the depth of snow.” She said that generally, the temperature below the snow increases by about 2 degrees F for each inch of accumulation. In addition, the soil gives off some heat so that the temperature at the soil surface can be much warmer than the air temperature. “One study found that the soil surface temperature was 28 degrees F with a 9-inch snow depth and an air temperature of -14 F!” she said.
“Snow brings welcome moisture to many landscape plants, which will in turn help prevent desiccation injury,” she said. “Even dormant plants continue to lose moisture from twigs (as water vapor) in the process known as transpiration.” Evergreen plants, which keep their leaves through the winter, are at even greater risk of injury, she added.
On the other hand, some evergreens can suffer from too much snow load. The weight of snow and ice can bend or even break branches, particularly on multi-stemmed shrubs such as arborvitae. “Snow should be gently removed by brushing away with a broom,” she said. “Do not try to remove ice since it is more likely that you will break the stems.” She said that multi-stemmed shrubs that are known to be susceptible to breakage can be bound with twine to hold branches together.
Find Lerner’s original article at https://www.purdue.edu/hla/sites/yardandgarden/snow-is-good-for-gardens-2/.
Former Purdue urban forestry specialist, Linsey Purcell, wrote about excess snow and ice loads on trees. He offered 3 main tips when it comes to managing these loads.
First, do not shake limbs to try to remove snow or ice. He said when you find your trees are bending or drooping as a result of ice or snow accumulation, your first instinct is probably to shake the branches or knock the weight off with a broom or something similar. This may cause worse damage or actually cause the branch to snap off.
Note that Purcell’s advice applies to trees, rather than shrubs, and seems to caution against more vigorous activity with a broom than Lerner suggested.
Secondly, safely remove broken limbs. “Broken and hanging branches can be a threat to people and property,” he said. “If a limb breaks off from the weight of ice or snow and remains in the tree canopy, have it removed and the remaining stub properly pruned to the branch collar as soon as weather allows.”
Third, hire a professional. “If there is substantial damage to your tree, have an arborist examine damaged branches and limbs for signs of weakness and injury for reparations,” he said. “It is best to always hire an ISA Certified Arborist.” To find an arborist in your area, visit the website, www.treesaregood.org.
Finally, for DIY tree pruning when weather gets more bearable, download the publication, Tree Pruning Essentials, from the Education Store at Purdue University, www.edustore.purdue.edu.