– Agave macroantha (2013)
By Debra Gerber (August 2013)
Agave macroantha, aka black-spined agave, originates in the south-central Mexican states of Oaxaca and Puebla. Its native habitat is a rocky, arid and semi-tropical setting. With a winter hardiness of 20 to 25 degrees F, it thrives as a landscape planting in U.S. zones 9a to 11. In our area, roughly zones 5/6, it makes an excellent container plant, especially for beginners (which is good for me, since I have agreed to show this plant in the next HSCSS show).
A. macroantha tolerates a very broad level of soil alkalinity from 6.6 (neutral) up to 8.5 (alkaline). The plant has very low water needs and does well in full sun to partial afternoon shade. The only requirement this plant demands is a well-drained soil. For optimal growth and health, it is suggested that containers be wide enough to allow root growth and basal growth (suckers) be removed. Every two years, trim the roots and repot the plant.
When the plant prepares to bloom, it produces a slender, 6-foot-tall stalk with 10 to 14 side branches on which “purple-tinged green flowers with fuzzy interiors” appear. Hope you are a patient person, because Agave macroantha takes 15 years of growth before it blooms. After the blooms fade, small plants can be seen on the branches. These then drop off and continue to add to the “colony.” If you don’t want to wait, this plant can be easily germinated from seeds or propagated from the ground-level basal shoots.
I will end with these last two facts. A. macroantha is one of the few agaves from Mexico that can be fermented to make mezcal, a smoky-flavored liquor. Second, after reading this article you have a desire to see this plant in its native habitat, a round-trip ticket from St. Louis to Oaxaca, Mexico, will cost $769.03. The flight will take approximately 10 hours, 55 minutes.