Vallisneria americana (Tape-grass) in the lower St. Johns River, FL, is exposed to variability in salinity and turbidity. From 2002 to 2011, we compared mean blade length, plant depth, and bed width between residential and natural shorelines, the western and eastern sides, and river sections of 64–80 km, 81–96 km, and 97–112 km from the river mouth. Leaf blades of eastern plants were 27.0 cm longer and were found in 0.57 m greater depths, a pattern possibly related to seasonal westerly winds. We observed no differences with land use. Blades were 20.0 cm longer in the farthest section where salinity concentrations were 1.35 ppt lower than in the 64–80 km section. Following hurricanes, resilience depended on pre-storm bed health and post-storm water quality.