Mizshelli;
I work for the local school district here in southern Colorado as a groundsman, and over the years friends and neighbors have asked me to keep my eyes out for certain plants for them. On more than one occasion these plants were Yucca, so I can say this with absolute certainty that they will grow back with little help, but... only after a year or two. Keep in mind, Ma'am that these are local natives replanted in the same environment, so I'm not sure yours are the type that grow here. I don't know if I was all that helpful, but I do know that Yucca's have deep roots, so be ready.
Good luck!
