Recently Jill B asked about pruning an old clematis. I have another
question:

We have a clematis about 20 years old growing up our extension: enormous
it is, though not as pretty as Jill's. I hack it back every year with
the hedgetrimmers, but: what about the roots? It's rooted right beside
the foundations, and I sometimes wonder what's going on down there.
Some of the stems (trunks) must be about 4" across last time I looked:
should I dispose of this one, and plant a new one?

John