The previous owners / tenants of the house we bought, planted 2 rubber trees both of them less than 1ft away from the house. The trees had got to be approx 7-8ft tall.

After reading and hearing about issues related to the potential for foundation damage with rubber trees, I relocated one far away from the house and removed the other.

I got most of the 15 ft (!) roots out, but there's a few left.

Do I need to keep digging up my yard and completely remove them, or now that the trees are gone, is that sufficient?

Is there something I should put on them (I do not want to use pesticide / chemicals) to ensure that they do not sprout or is this not possible for roots alone?

Thanks,