The daylily Double Blu By-You was hybridized by DuPaul in 2010. Double Blu By-You was hybridized by crossing (Land of Cotton × sdlg). The color of Double Blu By-You can be described as blue violet blend with violet eye and edge above yellow green throat. It is a Diploid. It has a Double 100% form. It has a bud count of 21. It blooms in (Midseason,Rebloom). It's flowers measure (6 in, (15 cm)). It has 3 branches. It has a normal scape height of (32 in, (81 cm)).