Mother's Garden: How does snow affect your garden?
This New Year, gardens are covered with snow, in one's own backyard, as well as in the woods and meadows. Snow frosts the trees and the garden. It sparkles in the sunlight. It's another lovely white winter.
We may have broken the record for the snowiest December in Boston history; the previous "winner" was 1970 with 27.9 inches. Will the traditional January thaw come this year and reduce it all to dirty, slippery ice, or will we have to wait for spring to melt it all away?
A more interesting question: What does snow do to gardens, what does it portend for the next growing season and what should one do now?
On the whole, snow provides a good warming blanket, protecting flower buds, plant crowns and even roots from very cold temperatures in the soil and intensely cold air. Also from repeated freezing and thawing which dries out plant tissue. This desiccation is the cause of the spring browning we call "winter kill."
Perennials are the major beneficiary of snow protection, particularly the latest "fashion flowers" in catalogues and magazines. In truth, many of these are not nearly cold hardy enough and couldn't survive a "bare" winter. If some snow cover remains until March, next summer will be a banner year in the flower border.
Marginally-hardy rose bushes benefit from this white blanket protecting their buds and grafts. Snow also protects the flower buds on the lowest branches of hydrangea, azaleas and rhododendrons.
Incidentally, by reading the leaves of rhododendron, you can reliably tell the outside temperature without looking at a thermometer. The leaves curl more and more as it gets colder and colder. If you calibrate the amount of leaf curl with a thermometer at several different times, you will be able to read the leaves quite accurately.
However, each rhody variety curls a different amount at each temperature. Most start hanging down below 40 degrees, and curl at about 32. When they are tight like cigarettes, it's down near zero (Could this keep children busy on snow days?)
Snow can be a bad thing too. While the light fluffy stuff makes a gentle blanket, heavy wet snow or ice becomes a crushing burden. Trees bend and split, especially branches that are too long. Over-weighted branches often break.
What you should do when heavy snow and ice happens requires care and thought.
When cold and frozen most plants are very brittle and easily broken, especially twigs and buds.
For ice, leave it alone. Except for attending to dangerous trees and branches wait for warmer weather to melt it, and to do needed repairs.
However, branches bent low by very dry snow may be shaken off by VERY gently pulling the branch. Don't use a broom. As branches are freed from the snow's weight, they usually spring up by themselves from the tension in their wood. If they don't, leave them to recover alone.
If branch ends are actually buried and being bent lower and lower, especially as the snow melts, they may need some help. But gently! Try to carefully free the branches by going beneath them with something. A broom handle is Ok here but don't hack away with a sharp shovel.
Go easy with pruning to correct things at this time of year. Better to wait until late February or early March when the threat of a below zero freeze killing cut ends is less, and the plants' spring hormones start running. In the meantime, Mother Nature will do some of her very messy pruning for you.
Ruth S. Foster is a landscape consultant and arborist. More gardening information can be found on her Web site: www.mothersgarden.net.