Plant Highlight: Agave flexispina
Agave flexispina is not often seen in horticulture, but the combination of compact blue-gray rosettes and good cold-tolerance make it an excellent garden plant. In nature, it is found in grasslands and open woodland areas in southern Chihuahua and northern Durango, in northwestern Mexico.
In its native habitat, Agave flexispina does not get very big, with the rosettes generally measuring about a foot to a foot and a half across (30 to 45 cm). It typically makes a few offsets, though sometimes plants may remain single. In cultivation it often grows larger than this and puts out more offsets. Our largest plants at the Ruth Bancroft Garden have reached a diameter of a little over 2 feet (60 cm). This species is not as long-lived as many other kinds of Agave, and our three plants flowering at the Ruth Bancroft Garden this year are only 9 years old from seed. Undoubtedly plants in the wild would be a little slower to reach maturity.
The flower stalk of Agave flexispina is on the slender side for an Agave, and in habitat it reaches a height of 8 to 12 feet (2.5 to 3.5 m). At the Ruth Bancroft Garden, our largest specimen exceeded this, topping out at 20 feet (6 m). The stalk may be straight or else just a little sinuous in the upper half. The upper portion of the stalk has relatively short branches, each ending in a cluster of flowers.
The flowers of Agave flexispina are about 2¼ to 2¾ inches long (5.7 to 7 cm), not counting the stamens and pistils which extend much beyond this. The lower portion of the flower is green, with the tips paler and more of a yellowish-green color. The tips of the buds are often tinged with reddish-purple, and in some plants the purple tinge extends over the whole flower. The stiles and filaments are purple, with the pollen-bearing anthers atop the latter having a pale yellow color.