With rapid and extreme fluctuations to our climate increasing over the last few decades, we’re finding frost injury a more common occurrence. It has been commonplace here in southern NH to have warmer than average fall temperatures with some unseasonably frigid days, wreaking havoc on plant tissues sensitive to drastic fluctuations. Similarly, the early spring has been warmer on average, leading to early bud break and subsequent injury when temperatures sink to average or below.

We had fluctuating temperatures during the winter of 2016-17. There were numerous days in late January and early February that were well into the 50’s  followed up with lows of subzero. We had daffodil bulbs emerging from the ground at the end of January that were then affected by the significant cold that followed. We attempted to cover the emerging growth with salt marsh hay with very marginal success.

Late frost in the early spring also took its toll on early flowering trees. This can be common in trees and shrubs such as, Lilac, Viburnum and Magnolia. Our Magnolia’s had very weak flower displays that spring, less than 50% of normal. The health of the trees was not compromised, however, and some of the trees produced sporadic summer flowers.

For more information on frost injury and other winter damage click on the link to Cornell University. http://plantclinic.cornell.edu/factsheets/winterinjury.pdf