Posted: 29/08/2012 at 17:40
I agree. I have poplar saplings coming up in my garden. The tree is in next door but one's garden - a massive tree. I just mow them but sometimes have to remove the root as it becomes woody close to the surface of the lawn.
Could you post a larger image of the leaves of the problem plant, we might be able to positive id. it and help to find the source?