The requirements for this grass tree to be successful are full sun, well-drained soil and no or minimal summer water. It is cold hardy to at least 15 degrees, can withstand severe drought and grows in Sunset zones 11-24. The only disease it may encounter is root rot if the soil is too wet. It is pest free, deer resistant and fire retardant. Weeding around the base is the only challenge you will have with this carefree plant.
By my best estimates, this particular specimen in the photos is about 17-18 years old. I transplanted it from my previous yard in January 2007 where it had been in the ground for about five years. It was in a two-gallon pot when originally purchased. This last October it started putting out its first-ever flower spike and now six months later, is easily 12' tall from the ground. There are numerous pollen-laden small white flowers on each node that emerge from the stalk about half way up it-far too many to begin to count. The bees are constantly visiting it and I can hear the din of them from fifteen feet away.
There are 20-22 species in the genus Dasylirion that belong to the Dracaena family. As the plant slowly grows, a thick dark trunk becomes visible. Older leaves droop around the base and can be trimmed off as with palm leaves, or left to form a shaggy buttress that collects water and provides support and habitat. I will not outlive my beloved grass tree as they can survive to 150 years or more, but I enjoy it daily and am amazed at its awesome blossom!