Last year I did a test using the abundant duck weed that chokes one of our
new ponds. It formed a pretty solid mat around some grapes and permitted
only well rooted perennial weeds to penetrate. It lasted clear until this
spring.
My particular need is for someting I can place around closely spaced plants
that will not also be a nursery for field mice. Sawdust could be used, but
mice can use it and it doesn't seem to stop weeds unless it is quite deep.
So I waited this year until the wind pushed the duckweed all to one side,
took a good leaf rake and in short order piled up quite a few wheel barrow
loads. Waited a day for it to drain and it becomes light and fluffy.
Later I hope to try and idea of casting a rope across a narrow part and
hauling in a truck load with the tractor. Might get enough to use in the
orchard.
Of course commercial mulch stops weeds, but I haven't figured out how to use
it for small irregularly spaced seed bed plants. Del, frost last night,
sunny today
Del Stubbs www.pinewoodforge.com ag zone2/3