Keep Mower Height Higher
Set the mower height set at 2-1/2 to 3 inches from now on. Grass growth is slowing down but the sun is still hot enough to scorch the blades if you mow too short. Plus longer grass shades weed seeds and can help reduce their germination.
Water Newly Planted Trees and Shrubs
Don't rely on nature to provide enough water for trees and shrubs that you've planted this spring or summer. The roots will continue to grow into the fall until the soil is about 45 degrees, and deep watering once a week will encourage these roots to go deeper.
Welcome Some Rose Hips
Roses need to start their hardening off period by the end of August. It's hard to refrain from cutting the flowers but allowing some to form hips will help signal the plant to begin this process.
Stock Up on Mulch
Begin gathering a supply of mulch to spread around tender perennials, roses, trees and shrubs once the ground has frozen. If you mulch before then, the ground will be delayed in freezing, and rodents will begin making tunnels in the soil under the mulch to find a cozy home for winter while they munch on your plants.
Rake Up Rose Debris
Begin removing the old mulch under roses and raking up all leaves and debris. While this organic matter may seem beneficial, there are many rose disease organisms and insects that overwinter there, and you can reduce the damage to your plants next year by getting rid of it all. Once the ground has frozen, cover the bushes and apply winter mulch.