Agastaches belong to the mint family, and, as a result, they all have square stems. They also have aromatic leaves and clusters of small flowers.
Commonly called Mexican hyssops, they can be perennial but only a few are hardy as far north as zones 4 and 5. The tender species are grown as annuals in the north and are perennial in the south.
Hyssops are easy going and make few demands. They grow in full sun or light shade and spread to make 2-3 foot clumps. Divide them in the spring, and they bloom all summer long delighting the hummingbirds but fortunately not the deer.
There is a lovely gold-orange variety Agastache ‘Kudos Gold' and a salmon-orange with rose and purple called ‘Apache Sunset', and there is a more compact variety 'Little Adder'(zones 6 to 9) featuring spires of lavender and purple flowers on each stem.
All hummingbird mints are upright in form and bloom all summer long. The bees, as well as the hummingbirds, enjoy them, and they are carefree and drought resistant once established. The flowers make welcome additions to bouquets, but the plants need good drainage.
These are good plants for an informal colorful, easy-care planting that will show up well from a distance.