My husband's parents are buried far away, in the arid high desert of New Mexico, elev 4000. There is no living family there, so we seldom have reason to go....but when we do, I feel awful about the condition of the gravesites. The soil is hard caliche, and there is no irrigation in the cemetery. Other than sand burrs, nothing is growing. It's a tough situation, but I'm very open to ideas. What would you plant?