2peas

Help! Our front lawn has 2 huge "naturalized" beds that have been infested with thousands of Norway maple seedlings so thick that it looks like ground cover! We don't use herbicides, so have already spent hours hand weeding. Even the mulch and thick leaves from last Fall has not stopped them although there are fewer in those areas. Will they all mature if we can't get to them? Are there any other ways to deal with them?