Hyssops are an exciting group of aromatic plants making a big splash in the plant world. Members of the Agastache genus, hyssops are known for their brightly colored flowers and for attracting hummingbirds and butterflies to the garden. They are generally hardy to USDA zone 5 Front Range gardens and many can be grown as annuals in containers elsewhere.
Many varieties of hyssops grow well in Colorado. These plants are cold hardy and can adapt to a variety of well-draining soils.
Honey Bee White hyssop is a four-foot-tall white, blooming giant suitable for the back of borders. Korean hyssop grows to two feet tall and features violet-blue flowers. CORONADO® hyssop is a 15-18 inch tall Southwest native perennial which bears orange-yellow flowers.
Hummingbird mint smells like bubblegum. It reaches two feet in height and three feet in width in full sun. The mid- to late-summer flowers are rose-pink.
Sunset hyssop is another favorite among gardeners. Sunset hyssop grows to two feet in height and bears orange flowers with lavender buds that are beautiful from mid-summer into the fall. Brushing against the plant’s narrow leaves releases a pleasant, root beer-like aroma. An added attraction is it provides nectar-rich flowers, which attract hummingbirds.
Sunset hyssop is hardy to an elevation of 7000 feet. It thrives in full sun to partial shade and average soil that drains well. Supplemental watering produces a larger plant. It is a beautiful companion for Russian sage, catmint, blue-mist spirea and a host of other Xeriscape plants.
Hyssop is best transplanted when temperatures are warm and are definitely not for fall planting. Avoid water-logged soils.