Bring on spring! After eight days of below zero weather and 25 days of below 32 degrees this month, I know that I am not alone in wishing that spring was just around the corner.
But it has not!
As a gardener you probably suspect such temperatures have caused damage to plants. Indeed it has — our below freezing weather throughout this month has caused the water inside plant cells to freeze, resulting in dehydration and the rupture of cell walls. Thus, expect to see shriveled and brown or blacken damaged tissue with the tips of many small twigs becoming limp and eventually falling off. Although it is too early to know how much damage has occurred, pruning should be delayed until spring.
Now is the time to come to grips with what we might observe upon the return of warm weather. First, our colder than average January temperatures have destroyed the emerging growth (buds) on numerous species, including Japanese maple, smoke bush, ginkgo, hydrangeas, magnolias and especially rhododendron and azaleas. Likewise, the flower buds on redbuds, dogwoods, and most other spring blooming shrubs and trees including many species of fruit trees, have been damaged. However, I am not predicting no blossoms — I believe we’ll see a diminished bloom.
Second, our strong (up to 35 mph gusts) winds coupled with the duration of below freezing weather has significantly contributed to plant freeze damage.
Third, newly planted young trees and shrubs might experience damage to their roots. Then too, marginally hardy trees and shrubs (in general those normally found growing south of us in southern Indiana, Illinois, Missouri, and Kentucky and further south) won’t fare well.
Fourth, expect sunscald or “winter burn” on needled evergreens including fir, cypress, juniper, spruce, pine, yew, and arborvitae species and boxwood, holly, and rhododendron which are broadleaf evergreens.
Fifth, anticipate frost cracks or vertical cracks on the stems of very young trees which have not developed a thick layer of bark. Damage of this nature usually occurs on the south and southwest sides of tree stems and young maple, apple, linden, and honeysuckle and species most susceptible to damage. These can be prevented by wrapping the tree’s stem with a tree wrap.
Having cited what I expect in the way of damaged to plants we have been blessed with a blanket insulation of snow and the fact that our plants were already fully dormant.
(Regarding winter hardiness zones, the U.S. Department of Agriculture has traditionally cited Indianapolis as being in zone 5b; however in 2012 they released an analysis of weather data between 1976 and 2005; and we were assigned zone 6a.)
Ed Myers (Emyers3670@aol.com) is a past president of both the Irvington Garden Club and the Garfield Park Master Gardener Association. Additionally, he is the steward of Irvington’s Benton House Historic and the Kile Oak Habitat Gardens.