With its astonishing blooms of vibrant orange-red and sunny yellow, this semi-cactus dahlia is sure to elicit gasps in a group planting. But all it takes is one of these plants to add some sizzle to a blah border or a so-so garden bed. Bon Bini Karma was bred to primarily be a cutting flower, as evidenced by its vivid colouration, sturdy stems and long vase life. It produces months of striking, fully double, 5½" flowers with pointy petals. Like most dahlias, it performs best in a sunny location and in soil that drains well.