My grandma knew something about weeds that too many have forgotten: Hot composting is one of the best ways to kill the seeds. Better yet, hot composting does this without making ash, without a trip to the town dump, and without adding methane emissions at a landfill.
According to information published by the Weed Science Society of America, some weed seeds become non-viable after only a few days at 130 degrees. Others require as much as 30 days at 145 degrees. Some species even require a few days at temperatures as high as 160 degrees. While we home composters may not always achieve the ultimate hot operation, we can all create piles that get hot enough to make a difference.