‘Black Adder’ is a new introduction, a showy cross between Agastache rugosum and Agastache foeniculum that blooms from mid-summer to frost. The deep violet-blue flowers and dark purple calyxes are held on long spikes over nice mid-green foliage. ‘Black Adder’ is a great addition to a butterfly garden, and is a wonderful cut flower. Grow ‘Black Adder’ in a well drained garden loam for best performance.
Grows to 2 feet tall and 1 1/2 feet wide in full sun.