On Thu, 27 Jun 2013 07:58:46 -0400, Pat Kiewicz wrote:

The part you cut off is still alive, for a while.

Well, I've read about a dozen pages on the bull thistle, and, it
seems relatively easy to control (as long as you don't let it get
to the level I did).

http://en.wikipedia.org/wiki/Cirsium_vulgare

Apparently mine are two-year old plants (for the most part).

The yearlings only form low-lying rosettes, of which I have a
few. These radiating leaves don't produce a stem, so they lay
below the (lawnmower) radar, but otherwise don't reproduce.

The second year is when they produce the flowers, and then when
they flower, they die. The seeds don't appear to travel all that
far but they have an amazing germination rate (over 90%) so I'll
be weeding them for a few years to eradicate them.

The flowers are a rich nectar source, hence my bee will go
hungry in the next few days:
http://www5.picturepush.com/photo/a/...g/13422848.jpg