Winter Heaving of Peony Roots
Winter can be trying on peonies, particularly for the newly planted, less-than-ideally sited or poorly mulched. Flower buds can withstand sub-zero temperatures, but the continued freezing and thawing of more mild winters can result in what is known as heaving. This term refers to the resulting force of a layer of ice forming beneath the surface of the soil. The expansion of this ice pushes a layer of soil upwards. The cumulative effects of this process can be quite pronounced, particularly after a winter like the one we experienced this year with many periods of freezing and thawing. Its frost heaving which is responsible for delivering us a fresh crop of ‘Connecticut potatoes’ each spring, as rocks come up to the surface. So as you begin your spring clean up, inspect your peonies for signs of heaving.