This 26 Febuary 2018 video, from Wageningen University in the Netherlands, says about itself:
Scientists of Wageningen University & Research have been working on how to grow crops on Mars for five years now. For the growth of plant species, even if it is going to be indoors, there are more and less favourable places.
Using as much as possible of the available resources on Mars including regolith and ice seems wise. Wieger Wamelink and student Line Schug therefore developed an optimal Mars wide landing map, seen from a plant’s perspective. Some of the ideal landing places coincide with past and planned landing sites, however some do not.