‘Klm NN’ is a medium-sized, bushy-looking shrub with a spreading habit. It grows to a height of about 5 feet over time. Early green leaves change to a golden yellow in the fall. The flowers, which consist of four petals growing in tight clusters of three or four, are small, fragrant grape-purple petals that emerge from a purplish maroon calyx. As the leaves develop, the flowers fade. It is hardy in zones 4 to 8.