Yard work has been discussed a few times on the forum before - here are some links:
Sitters How Do You Feel About Mowing lawns?
Everyone is different - some sitters are happy to mow, while others will definitely skip the listing. If a HO wants mowing of a large property done, then they will need to be aware that it will limit their pool of applicants - however, there may be the right sitter out there for them. In general, it is fairly uncommon for a listing to ask for mowing & yard work (particularly for a large property). It is helpful when listings mention what exactly the mowing expectations are - if they have a ride-on mower, and how frequent is the mowing is.