An uneven lawn that features dips and bumps is not only aesthetically unpleasing and can twist ankles, but serves as a potential hazard for growing plants as well. Besides creating visual imperfection, dips or low spots cause water to accumulate, thus damaging the roots of plants and providing a safe haven for disease-spreading organisms. Instead of hiring a professional landscaper, level an uneven lawn yourself to save on costs. While smaller bumps are easier to level manually, adopt mechanical means to level large bumps.
Walk the lawn and inspect the size of dips or hills. Remove rocks, plant debris, log pieces and other objects larger than a golf ball from the area. Kick dirt mounds and ant hills and flatten them out.
Tap small lumps in the lawn with the back of a shovel and then rake to level these out. Small lumps caused by the natural freeze-thaw cycle or mole or groundhog damage are easy to repair. Rake raised trails of dirt and sod that run around the length of your lawn and firm these with your foot. These trails indicate the presence of groundhogs or moles and may require that you set traps if they occur again.
Aerate the lawn with a mechanical aerator if your lawn features lots of bumps or high spots. The aerator drills tiny holes through compacted soil, thus improving oxygen and moisture penetration and making it easier to rake.
Remove thatch and break down lumps in your lawn with a power rake. The tool also breaks cores of soil left behind after aerating it.
Insert a shovel three inches into the soil all around a low spot in your lawn. Slide the shovel under the grass section to pull it out carefully, along with the roots. Pour equal amounts of topsoil and compost over the exposed soil surface until three inches from the top. Tamp the soil and spray lightly with water before replacing the grass section over it. Position the grass section so it fits snugly. Press the replaced grass with the back of a shovel to establish good roots-to-soil contact.
Remove the grass over a large bump or hill that cannot be levelled with a rake. Repeat the process of inserting the shovel around the section and lifting it out of the soil, along with the roots. Break the mound of soil with a shovel until level with the surrounding surface. Dig into the soil a few inches to make allowances for the soil attached to the roots of the grass section you will replace. Tamp the soil with the back of the shovel to firm and adjust the dimension of the grass section before replacing it.
Install traps in your lawn to remove pests such as moles that cause holes surrounded by mounds of soil. Follow label directions when setting a trap near the hole to prevent injuring yourself. You may need to reseed patches of grass damaged during your attempt to level uneven spots. Spread the desired variety of grass seed over the bare soil and rake lightly to cover them 1/4-inch. Mist the area regularly until the seeds germinate.
Never use a roller to smooth uneven spots in your grass. Although using the roller is recommended to level the soil prior to planting grass seed, rolling an established lawn damages the turf, causing grass to grow thinner.