How are you killing the grass? What kind of soil do you have?

The grass is mostly dead now, using Spectracide & Roundup. Soil is pretty good - lots of earthworms, and it crumbles - not as much clay as sometimes in this area (St. Louis.) Hostas, peonies & such that I've transplanted (without really working the planting holes as one should) have done great. I'm thinking I might use an auger bit on the drill & loosen the soil about 6 inches deep & wide, then plant the seed to the proper depth & barely cover with mulch. Even this will be a lot of work with so many seeds to plant - any other shortcuts would be welcome.

It's worth a try. One thing about rototilling is that it will also expose more weed seeds and roots. Be careful to see how long after using the Spectracide and Roundup that you can plant seeds. I wouldn't put mulch right on top of the seeds, unless the mulch is very fine. You can mulch around the seeds, but not just on top of them. I used to have clay soil when I lived around Chicago. Through experimenting, I found that putting a little potting soil right below and above the seed worked for me. This may not be possible, however, with all of the seeds that you have to plant.

The other thing to think about is how to keep the weeds away in between the plants. This is where I highly recommend mulch. I used to put a heavy layer of newspapers down and then mulch on top. It was cheaper and the newspapers really kept weeds from regrowing. As a matter of fact, I stopped using weed killer. If there was a spot where I wanted to plant a garden, I would just put down the newspapers and the mulch. I'd come back in a few weeks and I could then plant my plants. Good luck.

Lynne- thanks for the info. I use newspapers & mulch in my planting beds. I've decided to start my seeds in trays - easier to control moisture & such. I would hate to spend all the time & energy planting the seeds & then have them fail. We're having such a dry spring - no sense watering the whole yard until I have to.