24-28" x 18-20" wide. (Cutting propagated.) A new hybrid cultivar just released for spring '09, 'Summer Glow' is a uniquely colored, long blooming hummingbird mint that begins flowering in mid-summer with glowing, pale yellow tubular flowers and dark lavender calyces. This vigorous plant has a narrow upright habit with bright green, non-scented foliage. Don't cut it back in the fall; leave the plant standing over the winter to improve cold hardiness. Zones 6-9.