Birds rely on a diet of large numbers of seeds, which might include the grass seed you have sowed to grow your lawn. One way to protect your grass seed from hungry birds is to cover it with plastic sheeting, which can be purchased at any home improvement or gardening supply store. This will allow you to grow the lush lawn you have envisioned.
Cut the lawn with a lawnmower to make the established grass blades even. Use the lowest setting on the lawnmower to make the blades very short. If the established grass is too long, it can prevent the new grass sprouts from receiving sufficient sunlight.
Run a pronged roller over the entire yard to poke holes evenly over the lawn. This will allow the grass seed to be distributed in an even manner, and will help the seeds receive enough air and water, which will help them grow.
Pour grass seeds into a seed spreader, and run it over the ground to spread the seeds evenly across the lawn. A seed spreader will have a container that holds the seeds, and a moving arm that continuously and evenly throws the seeds out onto the ground.
Attach a spraying tip onto a hose, and water the lawn well to ensure that the seeds will be properly hydrated before you cover them with plastic. However, avoid overwatering the seeds, which can lead to seed rot.
Cover the entire lawn with plastic sheeting. Depending on the size of your lawn, you may need multiple sheets to cover the lawn properly. The plastic sheeting will keep birds from eating the seeds from the lawn.
Push pegs through the plastic sheets and into the ground around the edges of the sheets, so they stay in place. Leave the plastic in place overnight through early morning on the following day, then remove the pegs and the plastic sheeting.