Remove any tall plants or trees that shade the pavers. They prevent the grass from getting full sunlight, which most grasses need to thrive.
Avoid using nonselective herbicides or weed killers elsewhere in the yard on windy or rainy days. The weather may cause the herbicides to run-off into your walkway, which will kill the grass. Do not use the chemicals on plants next to the walkway.
Water the grass between the pavers once a week during the summer to keep it from drying out. This will also keep your pavers rinsed and free of debris.
Sprinkle top soil between the pavers, if you laid the pavers on a sand bed and the grass looks weak or thin. Fill the pavers halfway with the topsoil. This will allow more grass seed to take root in the joints.
Apply a balanced, all-purpose lawn fertilizer to the grass during the growing season. Follow the package directions for instructions on application.
Avoid using rock salt or other chemical deicers on the pavers during winter. They will harm the pavers and may kill the grass.