Widespread and common, the exception being the low flat areas of the Champlain Valley where its occurrence is sporadic. Also appears to have a diminished presence in the southern piedmont, though this area is less heavily surveyed. May be found at the same locations as its look-alike, Marsh Bluet (E. ebrium), but in many cases one or the other either dominates the site or has an exclusive presence. McPeek (1989) has found that Hagen’s Bluet is more likely in fish-inhabited lakes not subject to winter fish kills.
June 3 – August 14