On 2010-08-18 15:53:28 +0100, ellison
said:

[snip]

FWIW, I have the same problem without having cut down any of my
poplars. They do have very far-flung roots and the suckers will always
grow. My lawn is dotted with them at the moment and it looks worse than
usual only because I haven't had enough grass growth to warrant cutting
the lawn for the past 6-8 weeks.