Yesterday I discovered Japanese knotweed. It has the softest stem for
cutting, and one stalk grows to be huge! Today I researched it some
online. It's not invasive in clay soil, nor does it sprout from seed in
the north, or without pollination from a separate male plant. It's said
to be capable to producing 25 kg of biomass to the square meter, of
about 5 pounds to the square foot!
Bill
S. Oregon coast
[Homestead] Biomass Crop Supreme,
Bill Jones, 04/18/2008