The methods by which shallow fresh-water plants spread can be easily determined by anyone who has access to a pond or lake shore where he can observe them. However, a man equipped with only hip boots cannot observe rooting structures of plants in water from five to seven meters deep. Very little information is available in the literature on the growth and spreading of deep-water plants. This paper reports observations on spreading of deep-water plants made in Douglas Lake, Cheboygan County, Michigan. Apparently the species of aquatic plants observed do not usually reach the area of the deepest water (5 to 7 m) by rhizomes from shallow water. Winter-buds, seeds, and fragmentation, singly or in combination with various accidental agents such as fish or other animals, wind currents, water turbulence or underwater land slides generally enable these plants to spread into deeper water.