Mow your lawn. Every weekend. Even if you did buy the manual push mower, snubbing your nose at the riding gas-guzzling type.
Even if there is an acre of it, and you have long term plans of fruit trees, gazebos and reading nooks.
Because even if you want a lovely field of wildflowers, the grass will get so tall it will just fall over on itself and then it will die, leaving big ugly clumps of dead yellow gray grass.
And then your mom will have to buy a weed wacker and spend 22 hours getting the lawn back to normal. And the previous owners will tell you their friends complained to them that "the property has gone to sh*t".