Setting aside the rules for using dolomite lime in container gardening that Al has set forth in the 5-1-1 mix, I wanted to understand if I could convert the two-dimensional instructions on the Espoma Dolomite Lime instructional label into three dimensions. Espoma gives instructions for using dolomite lime per square foot. As a container gardener, I need to add a certain amount of dolomite per gallon of soil (which is a cubic measurement). Obviously, Espoma is giving instructions for a farm or landscape application, which is why they focus on square feet. I need to convert Espoma's square foot instructions into cubic feet, for a container application. How "deep" in feet should we assume Espoma's instructions to be?

The columns A, B, and C below are the instructions that appear on the instruction label for Espoma Dolomite Lime. Column E is my attempt to get this down to tablespoons per square foot. Column F is where I need to make a guess. I converted to cubic feet - and then to gallons - based on an assumption that Espoma's landscape rules go down about three feet into the soil.

That guess looks wrong, because I end up in column F with amounts that far exceed Al's guidance for container soil applications. What am I forgetting to do here?