Q.How do you kill off neighbor’s volunteer aspen trees in my front yard
My next door neighbor’s little aspen grove has started to invade my front yard and I would like the best method to get rid of the volunteer saplings. I mow them down two to three time a week but they just will not die back. As this is in my lawn I do not want to use Round-up.

Certified GKH Gardening Expert
I understand that you may want to spray Round-up on the lawn, but have you considered painting the seedlings individually. If you cut the seedling and you paint the cut, the seedlings will die. The alternative is to keep cutting them down. They will eventually run out of energy and die off.
To keep new ones from sprouting, consider adding a pre-emergent like Preen to your lawn regimen. It will keep the aspens from sprouting and will help keep weeds down as well.