I have some kind of broad leaf plant growing on my compost piles that everyone calls velvet leaf. Has anyone ever heard of this? I have been making compost for the last few years and it is now ready to sell. However, I don't want to sell it until I know what I am dealing with here. My compost making would be best described as cold composting, as I only turned the piles 2-3 times per year. I started with 250 yards of pine wood chips and kept adding fresh cow manure, old hay, rotten silage. Now I have about 130 yards that is perfect, no signs of any wood chips in it, unlike the competition.

I also have another 150 yards that is about a year away. Is there any way to sterilize the compost to kill the weed seeds? I'd hate to have to try to hot compost this stuff, as it would be additional time. Also I have been told that the velvet leaf seeds will survive in the ground for fifty years, so I would be worried about that I would never be able to fully get rid of the seeds in this location. Thanks.
Dave