What would you do with this rental property back yard?

[Joe P.]

Looking to see what other landlords would do with the back yard at this rental property.  Tenants will be responsible for yard maintenance.  The former owner's idea was to plant moss in between all the stones so they wouldn't have to mow but it ended up just turning into a weedy mess which I just cleaned up.  I'm open to any ideas but so far my thoughts are 1. keep the stones and just plant grass in between them.  2. keep the stones and find something else to plant between them that doesn't need mowed (no idea what though) 3. get rid of all the stones and plant grass.  Right now I'm leaning toward just planting grass between the stones.  Tenants will need to mow a strip out front regardless.  What are all your thoughts?