Pine trees and soil
We removed three large (about 30 ft tall) Blue Spruce pine trees from our lawn. They had needle cast and were dying. We raked and removed most of the needle layer that had built up under the trees, then we did a root and stump grind. Now we want to plant two Black Hills Spruce and a maple tree in the same area. - How should we prep the soil for planting the trees and planting grass on what is currently bare ground (because it was under the canopy of the large pines)? - Should we add fertilizers or chemicals to the soil? - Should we scrape down to remove wood chips left over from the stump grind and bring in a layer of topsoil? If so, how much?
Dakota County Minnesota
Needlecast (Rhizosphaera) will likely remain on the site where your trees are removed. Black Hills Spruce is moderately susceptible to Rhizosphaera and so those trees have an increased risk of being affected. https://extension.umn.edu/plant-diseases/rhizosphaera-needle-cast-0
The spectrum of Needlecast diseases is changing and you should anticipate this as you plant. https://www.dnr.state.mn.us/treecare/forest_health/fid/spring-2018-articles.html
Other University extension divisions in our growing zone are stating that Norway spruce is much more resistant to Rhizosphaera and this might be an option for you.