Q.How do zinnias look when the first frost happens?
This is awkward, but I’ve had zinnias for numerous years and when they die for the winter, they tend to dry up and become brown and crispy. I recently moved into a new place and planted beautiful zinnias. Last night was probably what I would consider the first frost where I have seen ice. This morning when I came out, my zinnias were droopy, wilted, moist and an olive green. They look and smell like there is old fryer cooking oil on them. No one else’s flowers on the block seem to be affected by the cold, just mine. So my question is, is this what flowers can look like that have been hit by cold, or am I the victim of someone’s prank? 🙁 the day before this they were colorful, bright and healthy.
Certified GKH Gardening Expert
This is definitely a case of cold weather. Some flowers are more tolerant than others, even within the same species. They should begin to die off for the year at this point, and often even before this time.
It looks like you had a freeze, not just a touch of frost. (freeze =28 degrees or less for several hours) A freeze turns the water inside plant cells to ice. Water expands as it freezes which tears the cells. As temps go back above 32 F., the ice melts and the plant structure, ruined by the expanding ice, crumples. A frost isn't so dramatic. It may turn flower petals brown and result in brown or black leaves but the stem is still intact. Annuals are more sensitive to frost than perennials.