I've had good luck with it but in alot of spots that I put out in late summer/early fall, it wasn't touched till the next year. I don't think they have any use for it come October but they will tear it up in the summer! ( I use the powder form).

What type of soil makes a difference also. A harder clay soil is the best. I have some spots that have been out now for 3 years and there's an area the size of a truck bed tore up.