In message , Pam Moore
writes
Is it possible to grow watercress without running water? Has anyone
tried, and if so how can it be done? Pieces of bought watercress will
root in water, but is there a way of growing them on? I often end up
wasting the last of a packet.

Pam in Bristol

If I'm not mistaking some other white-flowered crucifer for water-cress,
then some of the localities that I've seen it growing wild are standing
water rather than running water.
--
Stewart Robert Hinsley