The average last date for frosts in northern Michigan is mid May, according to the Farmers Almanac. Depending upon the particular species of tropical plant grown, some tropical plants suffer damage when temperatures dip below 60 degrees Fahrenheit. Place plants outside when frosts have left the region and temperatures have warmed, approximately in late May.
About this Author
Joyce Starr is a freelance writer from Florida and owns a landscaping company and garden center. She has published articles about camping in Florida, lawncare, gardening and writes for a local gardening newsletter. She shares her love and knowledge of the outdoors and nature through her writing.