This lovely Mexican species has proven to be hardy to 8 degrees F in our zone 7b garden, despite books that proclaim it to be a Zone 9 plant. Each 4' wide rosette of narrow green foliage will eventually find itself atop a 4' tall trunk. Be sure to plant this prior to puberty (yours), if you really want to see a full-size trunk before you die. Our 10-year-old specimens are 3' tall x 4' wide but showing no sign of a trunk. The unique feature of D. acrotrichum is the attractive, frayed leaf tips that are especially evident in winter...a truly bad plant hair day!