To prep the soil for the new grass I rented a rototiller and went to town. The rototiller was a big rear-tine job that was about $50 for a half day to rent. I was figuring it would chew up the lawn down to about 8″ and break up all the old dead grass, burying it in the dirt. No such luck. First off it only goes down about 3 or 4″ and it misses the section right in the middle. If you’re good at it I’m sure you can jsut make overlapping passes and cover the whole area very well, but I’m not good at it. Therefore in the best places it went 3″ deep, but there were significant sections where I didn’t do anything. Even in the spots that it did well with it didn’t really break up the old grass, and so there were tufts of it everywhere, causing big lumps.
Running the tiller was also exhausting work, and even though it only took two hours, I was beat by the end of it. What I should have done was to then use a garden rake and hand tiller to get rid of the clumps and break up the spots I missed. I did get rid of a bunch of the clumps, but not all of them, and this turned out to be a big mistake.