For a really lumpy yard, you need to core aerate. This is not optional; it’s a game-changer. Rent a machine that pulls out little plugs of soil. It loosens the ground, which makes flattening way easier.
Walk the aerator over the entire lawn. It looks like a woodpecker had a party on your grass. Don’t panic. Those little soil plugs are good. They break down and feed the lawn. Then, grab a heavy lawn roller.
Fill the roller halfway with water—don’t overfill it, or you’ll be fighting the thing. Roll across the whole yard in a crosshatch pattern. You’ll immediately see the bumps settle down. You might even feel a little smug.
The “Topdressing” Magic Trick
This is where it gets fun. You don’t need to rip up the whole lawn. Just topdress it. Get a big pile of screened topsoil or sand. A sand-and-soil mix is best. It levels out without getting rock-hard.
Use a shovel to drop small mounds of the mix into the low spots. Don’t bury the grass; that’s a rookie move. Spread it thin—like spreading frosting, not concrete.
How to level a horribly bumpy lawn without heavy equipment – Artofit
Take a stiff broom or the back of a rake. Work the mix into the grass so it settles around the base of the blades. You want the grass to peek through. Repeat this process every few weeks. The grass will grow right through it.
