This isn’t a serious question, more like a thought experiment. How would you design yard work to help build mass and strength? What modifications could you implement in typical yard and home maintenance to enhance its effectiveness as a workout?
Eliminate all power-assisted tools.
Create yard furniture using heavy materials.
Dig holes for garden beds.
Construct a fence.
Ask an indecisive friend for advice on where to plant new plants. Dig the holes and plant them, then have that person return to suggest better placements and move them accordingly.