Liquid Manure is regularly made at PermacultureVisions demonstration site. Noxious weeds were stored in an air-tight, dark container. We bought these containers at the local recycling center which is next to the rubbish tip. Water was added and then it was left to rot for months. The amazing thing was that the form or shape of the tubers hadn’t changed much which did scare us at first in case we hadn’t waited long enough, but after 18months it proved to be ok. The weeds didn’t pop up again out of the residue.