Abstract: Method and apparatus for mounting a disposable grass collecting bag to the discharge chute of a walk-behind mower. The bag is received in a grass collector having one end mounted to the mower handlebars and another end mounted to the discharge chute over the disposable bag. The collector mounting to the chute also secures the bag on the chute. During installation, after the bag is mounted about the chute, the body of the bag is folded and placed into the chute. The collector is then mounted to the mower with its inlet about the chute. When the lawn mower is started, the air flow through the chute will expel the bag into the collector and then inflate the bag in the collector to be ready to receive grass clippings.