What: Agastache ‘Blackadder,’ also known as giant hyssop or hummingbird mint, features dark red-purple flower spikes peppered with tiny mauve blooms. These are a favorite of hummingbirds, butterflies and bees throughout the summer and early fall. The blue-green leaves are aromatic with an anise or licorice scent.
Where: This clumping perennial grows best in full sun and average to sandy soil, but it must be well-drained.
Size: “Blackadder” giant hyssop will grow to be 3 feet tall with a spread of 2 feet in 10 years.
Care: Occasional watering — every 10 to 14 days — will keep this plant fresh looking during dry periods.
— Richie Steffen,
Great Plant Picks