Steam report
 

I was intrigued after reading about using steam for weed-killer.
So I tried it using this little Shark steam cleaner that is about
the size of a small shop-vac and has a wand that the steam
comes out of. The using up of the steam reservoir, requiring
a rest to let it cool off and a refill, is not so fast that it
becomes annoying (you can treat quite a few square feet
before having to stop).

One caveat: a quick pass over the weeds, like one might
use if spraying with an herbicide, does not work well. You
have to dwell on the weeds a bit with the steam before
it will kill the top growth. I went over a hundred square
feet with lots of wild bent grass, creeping buttercups,
and various miscellaneous weeds. While a few died instantly
from just a quick pass over with the steam, the bent grass
and buttercup barely noticed it. With tough weeds, you have
to stand in one place and basically steam the weed until it is
dripping hot water before you see any effect. (Actual boiling
water may be more effective for this.)