Two attractions to this plant: 1) very long blooming period (all summmer), 2) has the most aromatic foliage we've every experienced. Flowers are pink in colour and about 1" in length.

Blooms from seed its first year.

We have it growing in shade and partial shade. Gets 10" in height.  Spreads into a clump 24" wide, but is not so much of a spreader that I'd call it invasive.

Usually rated as cold hardy to Zone 5, but is likely hardier than that.

Somewhat tolerant of dry, shady conditions (a difficult location to grow perennials).

Glen's score:  7.