Tomato wilt was found to be killed in a compost pile after 21 days at a minimum temperature of 149 degrees. That is a lot of days to be able to keep a compost pile that hot, but it can be done. Not sure it is worth the risk.
http://www.planetnatural.com/c...
There are lots of things that can cause "wilt" in tomatoes, but as long as the soil is not being used for related plants, like peppers, etc. I would think using it for the lawn would be fine.
