I think you'll see a variety of answers to a question such as this.

We have some sandy loam soils that you can plant most any depth you want and it will come up, it just depends on how long you want to wait for it to get up and growing. We aim for 2-2.25" in these soils.

We also have some gumbo that you are better off planting at 1" than 3". We aim for 1.5-2" MAX in these soils.