I am a longtime daylily grower and hybridizer currently hybridizing Barth Daylilies for O'Donal's Nursery in Gorham, Maine.
My father started Barth Daylilies in 1952 and introduced a few red tetraploids. He is considered a pioneer in tetraploid hybridizing.
O'Donal's purchased the exclusive rights to Barth Daylilies in 2010. I started my own daylily hybridizing in 1989. Pictures of 14 Barth red tetraploids in various shades are below. ABNAKIS (My Dad's) SHEEPSCOT VALLEY TOPPER, LITTLE RED TREAT and DREW NICHOLAS (mine) are the best true red tetraploids. All are very hardy for the northern daylily grower. Barth Daylilies are also known for branching and bud counts.