On 18/03/2012 13:47, Baz wrote:
Martin wrote in news:vUh9r.458
:

I have found that this weed does not grow in my potato bed or parsnip bed
after initial weeding. Why? No idea.

Potato would be classed as a pernicious weed if the tubers were not
edible. I can almost never avoid having volunteers sprout in the borders
that have spent a season growing in the compost heap!

--
Regards,
Martin Brown