Review Of How Cold Can Ranunculus Tolerate References. Web deadhead your ranunculus as the flowers fade to encourage more blooms. Tolerant of low temperatures, but not surviving being frozen (1 to 5).

Web temperatures around 55°f are ideal. Web for those in usda zones 7 and colder, ranunculus are grown as cool season annuals because they go dormant in temperatures hotter than 75 degrees. Even in the coldest zones, you can still overwinter your corms and replant them the following season.