According to the University of Florida IFAS Extension, the lifespan of Lombardy poplars can reach 20 years; however, most succumb to stem canker disease at between 10 and 15 years of age.
Factors that affect the lifespan of Lombardy poplar trees include planting conditions, sun exposure and disease. Some factors can be controlled. Stem canker disease is untreatable, according to Ohio State University Extension.
To extend the lifespan of your Lombardy poplar, plant the tree in well-drained soil and full sun.