Question
when weeds are composted, when and how to i apply to my lawn? how long does it take to compost these weeds & will lime excelarate the decomposting?one season or more time to be sure the seeds from the weeds are dead.  how do you spread this compost with the least amount of time & effert?

Answer
If you compost so that the pile gets very hot, the weed seeds can be killed. If you allow the compost to decompose without it becoming very hot, the weed seeds may survive. Therefore, I can not say conclusively if you can avoid weeds from adding compost to lawns.

Do not add lime to your compost pile unless you use a large amount of very low pH products, such as citrus fruits. Most piles are very acidic which is required for the pile to work. It used to be recommended to add lime to compost, which today is no longer recommended.

Compost can be spread via a wheel barrow and a shovel but it is big work. I know some people who turned a landscapers roller into a compost spreader by making holes in the roller. It still takes quite a bit of time. You can also buy a "Hopper" which is an attachment to your riding lawn mower which shapes compost out. This is not a common attachment unless you have access to professional supplies.