Ideally your compost pile will heat up enough during the decomposition process to kill most of the unwanted bugs and weed seeds that get into it. Sometimes this isn’t the case and you need a little extra help. You have a couple of options, some are more harsh than others and you want to balance your desire to kill the weed seeds and bad bugs with your desire to maintain the life of the beneficial organisms that are part of your compost.
First and foremost of course, is trying to avoid weeds seeds and bugs making it through the decomposition process in the first place. One of the ways that you can ensure weed seeds are killed, is to put them in the hottest part of the compost pile, the center. If you’ve plucked some weeds from your garden that have gone to seed, make sure you bury them in the center of the pile and not along the outer edges where it doesn’t heat up as much.
Pasteurizing in the Oven or on the Stove
Sometimes weed seeds and bad bugs make it past the decomposition process, that’s when you can turn to pasteurization. This process is similar to sterilization and solar sanitization, but it is done at a lower temperature. The idea being that you heat the compost enough to kill the weed seeds and bad bugs, but not so much that you kill the beneficial organisms that you have worked so hard to cultivate. Work in small batches using fully decomposed compost and be forewarned, this process may make your house smell. Best to do it on a day when you can open the windows and let a breeze in!