Technically, Myers asparagus ferns are evergreen perennials, meaning they will grow back year after year. However, this depends on the growing location. Because Myers asparagus ferns are native to a tropical climate, their roots cannot survive freezing temperatures. Therefore, if left outdoors over the winter in a USDA hardiness zone below a 9, Myers asparagus ferns will die. To prevent this, plant your ferns in a container and overwinter them indoors.