It used to be that we were advised to amend the native soil when refilling a planting hole but this is no longer recommended, unless the native soil is really terrible. If amendments are needed it is better to amend the whole bed when you initially prepare it rather than just individual planting holes, and then topdress with organic material in future if needed. For more info on this topic see The Myth of Soil Amendments by Dr. Linda-Chalker Scott.
https://puyallup.wsu.edu/wp-co...
Also:
http://joa.isa-arbor.com/reque...
Daniel, I'm wondering why you are listing both sulfur and lime - do you actually mean whichever is appropriate for the particular situation? Usually we use lime to raise the pH and sulfur to lower it so I'm thinking you aren't suggesting people do both?
