free garden mulch - but only if you pull fewer weeds

[paul wheaton]

This video shows Helen Atthowe talking about penny cress.  If you leave it alone (read: don't pull it out or smother it like you might do with other weeds) it will reseed, grow in the early spring and then go dormant - providing your garden plants with a helpful mulch that does not compete.

http://www.youtube.com/watch?v=1_fBY5UG-Q4