Spring freeze protection means protecting roses from the harmful effects of late spring freezes on tender, vigorous new growth. Among the roses that are hardy in winter temperatures below 0°F/-18°C is a group that will survive winter but then weaken or die when new growth freezes during the spring. Pruning and fertilizing a rose in early spring promotes lush but tender new growth.
Late and unseasonal spring freezes may involve temperatures no lower than 20 to 24°F/-7 to -4°C. The effects can be devastating, killing new canes and leaving those that survive damaged and susceptible to canker. Late spring freezes do not occur everywhere. Rosarians who live in such climates resort to a number of strategies, including late pruning and minimizing spring fertilizer.
Consult local rose societies, rose nurseries and rosarians for advice.