It seems that most everything that grows in my yard is a volunteer. My flowers, my baby cactus and also some Mesquite Trees. I found three of them last year tangled up in other plants. Only 2 of them survived as Katie wanted to help me and took one right back out of the pot when I wasn't looking and it did not survive. But the 2 that made it are about 12 inches high now and seem to be doing great. Not sure that I ever wanted a mesquite tree as they are so messy and have thorns but they really are lacy and pretty in a desert sort of way.