Is winter production of cut flowers feasible in unheated high tunnels?
Based on research in Oklahoma, unheated winter production of crops like delphinium and lupine is not recommended in areas with minimum winter temperatures of 29°F (-2°C) or lower due to the likelihood of frost damage. However, frost-tolerant species including larkspur, snapdragon, and stock can withstand at least one night of 22°F (-6°C) with no negative effects.
