Old tires don't have to go to the landfill when they're no longer useful for transportation. You can color them in different colors and make a planter, make a swing for children, or you can make tire ottoman covered with fabric.
Haven't thought landscaping yet, but with a whole acre there must be a kids part in there somewhere, this would go great :) Gotta get my hubby to start this one pronto! Ladybug tire swing - 18 Amazing DIY Christmas Gifts for Kids
These are a nice decoration that can be made with recyclable paper to take away the guilt of takedown or just reuse them when you table needs some color! They are also great on a wall or dangling over a window.