Common annual plants freeze when the water temperature inside their cells drops low enough--and remaina low long enough--for ice to form. A temperature between 25 and 28 degrees Fahrenheit over several hours kills annuals and causes perennial dieback.
About the Author
Passionate for travel and the well-written word, Judy Wolfe is a professional writer with a Bachelor of Arts in English literature from Cal Poly Pomona and a certificate in advanced floral design. Her thousands of published articles cover topics from travel and gardening to pet care and technology.