Side green

Side green is the most sensitive stage to spring frost. This occurs during the flower bud opening, soon after bud swell, when flower buds are at the ‘water bud’ or ‘glassy green’ stage (Dennis et al., 1975).  Each phenological stage of flower bud development until ‘full bloom’ has a specific range of temperatures at which the bud is susceptible to damage (Dennis and Howell, 1974, Dennis et al., 1975) – See Greg Lang, MSU. Critical Temperatures for tart cherry blossom buds.  The initiation of bud growth in spring and the initial phase of the vegetative development are primarily driven by increasing temperature, while later during the season, growth is maintained in relation to the degree of competition of other environmental factors such as availability of soil moisture and nutrients, vapor pressure deficit, light, and temperature.

Source: Beedy T., C. Zavalloni, T. Wright, N. Rothwell, J. Nugent, S. Thornsbury and J.R. Black. 2005. "Cost to produce tart cherry in Michigan.” Risk Management Assessment Joint Report of UC Davis and Pileus Project. First draft under revision.