Can you put weeds in a compost bin?

No, diseased, live and treated weeds should not go in a compost bin even though yes, dead weeds can. Weeds that suffer from disease or treatment with herbicides or that still support living parts do not belong in the bin since infections may spread, synthetic materials may pollute compostable materials and viable plants may self-propagate. Dead weeds contrastingly will be compostable if previously "fried" atop exposed metal or within dark, sealed plastic bags.