K wrote:
Sue writes

"K" wrote
Janet Tweedy writes

Do you know the source of these streams? I have visions of people
chucking in watercress wherever they have running water and that
may not be advisable

Well, it is a British wild flower. They may get it anyway without
encouragement.

I'm sure I've read of water cress being grown in a garden soil bed -
presumably kept well watered. Or is that a different sort of cress?

I think someone on urg mentioned that within the last few months.
Rusty perhaps? Or Nick M?

But there is also 'american land cress' which tastes very like
watercress and grows in ordinary soil - I've no idea whether it's a
different species or simply a variety.

Barbarea verna, Joy Larkcom's book says. Watercress, of course, is the
real Nasturtium, and it will grow ashore, but has to be kept moist. But
then, so does American land cress, or it'll blow -- it's an annual,
unlike watercress. I found land cress very easy to grow, but it didn't
last long as I didn't keep watering it: it then duly self-seeded.

--
Mike.