Why are some annual flowers more tolerant of frost and cold weather than others? Part of the answer lies in the plant’s metabolism. The proteins, sugars, and moisture content of the plant affect its ability to withstand cold weather without demonstrating symptoms of cold injury, such as white or brown blistering or dead, water-soaked tissue. Eventually, most annuals succumb to damage caused by ice crystals, which form and puncture cell membranes at temperatures below freezing. Only truly cold-hardy annuals, like pansies and violas, can bounce back after a hard freeze. However, these eight annual flowers can form the foundation of your early spring and late fall flower garden, as they will tolerate light frosts without damage.
