How to Level a Bumpy, Uneven Yard

The best method for leveling a bumpy yard depends on the type of grass growing there. Lawns with bunching grasses that grow in clumps can be smoothed by top-dressing. Lawns with spreading grasses that form mats over the ground can be smoothed by top-dressing or a lawn roller. Causes of a bumpy, uneven yard include freeze and thaw action and castings left behind by earthworms. Earthworms and night crawlers prefer moist soil, so watering the lawn less frequently may encourage the worms to move deeper into the soil and reduce surface castings.

Top-dressing levels a bumpy yard by adding a thin layer of new soil. Top-dressing is an expensive method for smoothing large areas, but it is a smart choice for leveling a small area. The best soil for top-dressing is native soil because using a soil that matches the texture of the existing soil in the yard prevents layers from developing that could prevent water from easily penetrating the soil. Spreading top-dressing evenly over bumpy areas smooths the surface of the lawn and preserves the original grade. The best soil for top-dressing is free of rocks and other debris.

Top-dress your yard in spring, summer or fall when grass is green and actively growing. Add a thin layer of soil 1/4 to 1/2 inch deep, which allows the grass to adjust without being smothered. If you need to smooth out a large area, use a drop spreader or shovel and spread the soil the desired thickness with a rake. Fill depressions deeper than 1/2 inch over a period of months. Waiting three to four weeks between top-dressing applications ensures the grass has enough time to recover between applications.

A lawn roller presses down bumps in the soil with its weighted cylinder. Lawn rollers come in various sizes and weights and you can buy or rent hand-push models, motorized models and models you tow behind a lawn tractor. The hollow cylinder holds water or sand that provides the weight needed to compress the soil. Make sure the soil is moist before you roll the lawn.

Core aeration alleviates the soil compaction caused by lawn rollers. Core aerators remove plugs of soil from the ground using a drum covered with hollow tines. Spreading these plugs over the soil with a rake helps level the lawn and smooth any bumps left in the yard. Core aerators work best on lawns with a spreading habit, because using a core aerator on bunching grass can damage it. The best time to use a core aerator is when the lawn is actively growing and the soil is moist. Rental centers and home improvement stores often rent motorized core aerators.