Treating perennial weeds before composting
When using cold composting techniques, you are often advised not to compost perennial weeds as the roots will not be killed during the composting process allowing the weeds to grow wherever the compost is spread. The advice often given is to drown the plants by soaking them until they turn to “sludge” of to dry them on a rack. We use stacking bread trays as a drying rack with the plants exposed to the sun during hot dry periods. During wet weather it helps to cover the weeds and we have recently started using a builder’s bag to cover the rack keeping the roots dry and in the dark over the winter months.
It must be noted that many composters, including me, do not worry about perennial weeds being added to my pallet bins preferring to remove any surviving weeds at the sieving stage when composting is complete and a hoe to deal with any that try to germinate when spread as a mulch.
More information at Perennial Weeds
But if you dry your weeds the buildings bag is recommended and keeps the rack looking tidy.
More information on treating weeds can be found at www.carryoncomposting.com perennial weeds