(from the article `weather modification`) ...hail damage. Some operations have attempted to put so many nuclei into the supercooled parts of cumulonimbus that they would be almost totally ...
When the grass is laid on top of grasses already there, for encouraging new growth or for replacing the existing grass for a new season with a different strain, it is called overseeding.
Planting on top of an existing garden or lawn. Rye grass over lawns for winter. Wildflower seed in meadows.