Plant of the Month – Agastache rupestris

Plant of the Month – Agastache rupestris

by Josh Schechtel

Agastache rupestris, Threadleaf Hyssop
Family: Lamiaceae

One of the difficulties with a drought tolerant perennial bed is finding drought tolerant perennials that will bloom beyond spring. Many a bloom-filled May garden is a floral wasteland by the time July and August roll around. Many of us are still living in our gardens at this time of year, and it is nice to enjoy flowers later in the bloom season.

potm-Agastache-rupestris-1Agastache rupestris is a perennial that blooms from July through September, and provides a nice visual highlight as well as food for hummingbirds and native insects.

Native to higher slopes in Arizona, Texas and Mexico, Agastache rupestris is adaptable to both cool and hot summers. It will grow to about two feet tall, and produce spikes of coral flowers which grow from purple calyxes in a most attractive manner. The flower spikes project above the leaves, which are narrow and bluish green.

As with many perennials, deadheading can help prolong the blooming period into autumn. Unlike many perennials, the Threadleaf Hyssop grows well in rapidly draining poor soil, and prefers to be on the dry side. Too much water in the winter can cause it to rot, although it is nowhere as sensitive about this as many of the hybrid agastaches on the market.

An added bonus to this plant is the scent of the foliage. It has been described as smelling like licorice or root beer, leading to Licorice Mint and Rootbeer Plant as other common names. Chopped or crushed, the leaves are wonderful as a scented garnish in iced tea or sprinkled on fresh fruit.

potm-Agastache-rupestris-2Agastache rupestris is attractive to hummingbirds.


This article was originally published in our August 2015 Bulletin.