Mary Jo Babcock has been following the growth of this century plant for months. Century plants are agaves that are closely related to asparagus. What makes the bloom of the century plant special is that it only occurs every 10 to 40 years. When this happens, a large stalk grows quicky out of the center of the plant, reaching anywhere from 15 to 30 feet in height. After the plant blooms, it dies, l…