Okay, I've been preparing this area for about a year now. I had to start from removal of an obscene amount of brush, aggressive and invasive plant removal, to bringing hardwood-based compost (aged it's pH is 8.0 (1M KCl is 7.5) and was also used for the lawn renovation).

The soil itself is pH 7.2 (1M KCl is pH 7.1) and I was hoping the compost would have been more neutral. I will obviously have to switch sources for organic material. I collected a bin of leaves last fall (6' round by 6' tall) that I will be using. Those consist of hackberry, black cherry, and maple leaves mostly. There is a Pinus nigra and three Eastern hemlocks on the property as well.

I have planted eastern hemlock and Chinese hemlock, white pine, a couple white oaks, a few American hollies, and a couple big-leaf magnolias.

I will be planting the following for the start of my understory (I plan to propagate them by cuttings to fill in spots):

Kalmia latifolia 'Pristine'

Pieris japonica var. yakushimanum 'Cavatine'

Rhododendron 'Arneson Gem'

Rhododendron 'Bluenose'

Rhododendron 'Kerns' Violetta'

Rhododendron 'Purpureum Grandiflorum'

Rhododendron 'Summer Summit'

Rhododendron maximum 'RareFind selection'

The extension office's recommendations are for 5 lbs of elemental sulfur (90%) per 100 sq. ft.

Does this sound right? Should only spot treat the area I'll be planting or do you think I should do the whole area? The 'whole area' would correspond to the mulched areas in the photos.