Recovery of the bilberry (Vaccinium Myrtillus L.) from artificial spring and summer frost

Vegetative and sexual recovery of bilberry (Vaccinium myrtillus L.) was monitored in the field for three growing seasons after artificially applied spring and early summer frost. Bilberry recovered vegetatively (density and biomass) by vigorous production of new ramets and by production of large shoots in the damaged ramets. Recovery did not occur sexually (production of flowers), however. Summer frost was slightly more detrimental than the spring frost, but the difference was significant only in the percentage of flowering ramets. The results showed that bilberry is buffered against moderate frost injury. The rapid vegetative recovery guarantees survival of the plants after frost damage, whereas sexual reproduction may need accumulation of resources for many seasons. Consequently, the ability of bilberry to recover from sporadic frosts increases its potentiality to persist in a changing environment, where increasing temperature leads to earlier snowmelt in the spring, and increases the risk of frost injuries in plants that overwinter under snow.