Penhill Dark Monarch

Nobody quite agrees what color this flower is, and that is the fun of it. The registry describes bicolored purple and yellow. Triple Wren sees a raspberry-to-plum ombre. The RHS writes of swirling peach and dark pink. All are honest descriptions of a bloom that blends and shifts as it opens and ages. Walter H. Maritz bred it in South Africa, registered in 2002 and introduced in 2003 through J.T. Dahlias of Greenfield, Wisconsin, from a cross of Le Von Splinter and an unnamed seedling. Its sibling in spirit, Penhill Watermelon, runs even larger and softer in pastel watermelon tones, though you give up Dark Monarch's deeper saturation and its documented stem strength. Triple Wren's stock sells out, so shop early in the season.

An AA giant informal decorative with blooms of 8 to 10 inches on a plant Triple Wren grows at 48 to 60 inches. The stems are the headline, very strong for a flower this size, and Triple Wren reports it produces vigorously into fall when many giants slow down. Stake early and disbud if you want maximum bloom size. It holds an RHS Award of Garden Merit, rare validation for a dinnerplate in garden trials. Vase life is not well documented, so test a stem before promising it to a client. Expect the color to wander through the season, which is part of the appeal and part of the planning challenge for designers who need a repeatable hue. It suits growers who want giant impact without giant flopping.