A chilly week in March

Following a chilly week in March when temperatures regularly dropped into the teens, damage to flowers and emerging leaves was expected. The gardener’s question was, how much damage, and would injury to new leaves do harm as a late freeze stunted mophead hydrangea growth a year ago?

Flowers of Winter’s Star camellia were at their peak a week ago. Now (below), all are a golden brown, but with more pink buds opening.

The answer remains unclear as temperatures begin to turn warmer, with pink flowers on camellias beginning to open alongside ones that turned golden brown (above) earlier in the week. The loss of blooms of magnolias and camellias was anticipated, but damage to flowers of spireas (Spirea thunbergii ‘Ogon’, below) was somewhat surprising, though there was little history of such warm temperatures followed by freezes to go by. Injury to flowers of local weeping cherry varieties has been seen, and to the numerous flowering pears in the neighborhood and along fence rows of old farms where birds have deposited seeds for years.

Flowers of Ogon spirea a week ago, and after several nights when temperatures dropped into the teens (below). Emerging leaves of this yellow leafed spirea were not damaged.

Flowers of hellebores, mahonias, paperbushes, and the last of ‘Arnold Promise’ witch hazel survived intact, while blooms of Winter daphne were lost. The few stray flowers of ‘Summer Ice’ and ‘Eternal Fragrance’ daphnes were unharmed, with plump buds that should begin to bloom after a few mild days.

Of most concern going into the freeze were leaves of lilacs and hydrangeas that emerged too early after very mild temperatures through late February and the first week of March. New growth of the tree lilac (Syringa reticulata ‘Ivory Silk’, above) suffered slight damage, but less than anticipated, while small leaves of hydrangeas have been lost. While an April freeze damaged stems and early growth of mophead hydrangeas a year ago, it is too early to determine the extent of injury.

While no damage has been seen on new growth of daylilies (except by deer), some cold injury to early growth of hostas and toad lilies has been seen, though this is not expected to be significant.