Weed Drying Rack
Cold composting perennial plants can be a real problem as the roots or viable parts of the plant may survive the composting process and grow where the compost is spread. there is also a problem in separating some plant tops from the roots. There is more information at Perennial Weeds
For the most part we use two approaches to killing perennial weeds.
Drowning the plants soaking them in water until they decompose into a black sludge which can be added to the compost heap or
Desiccation: drying the plants until they are well and truly dead.
On the Stokes Drive Allotment Composting site, we use both approaches. The photo shows the use of bread trays (liberated from a skip) being used as a drying rack. This is open to the sun in the photo but is covered when it is wet. In addition to killing the plants they are easier to split for composting when dry and most of the soil has dropped off the roots.
Details of drowning perennial plants and using the resultant
liquid as a compost activator of liquid feed can be found at Plant Liquid Feeds