Thick stalks and root balls from a CBD harvest are mostly lignin and take a year or more to rot down whole, which is why they end up in the rubbish. Chopped small with loppers or run through a shredder they compost fine and add structure to next year's mix. A note on what to do with root balls from a diseased plant, which should never go back into the garden, is included on https://calmcbdseeds.com alongside the composting steps. Hemp stalk also makes decent kindling once fully dry.