"Thos" wrote in message
m...
Why don't you just pull them out?

Pulling plants out by the roots can disturb the soil structure, so it should
be avoided if possible. I usually cut my big plants down to a stub, and let
the roots rot over the winter, then carefully remove any big lumps if I need
to use that bed for seeds later. If I am using it for transplants, I just
leave the leftover roots in and plant around them.
--S.