Also, be careful to not plant it near any newly lain concrete. Lime can leach from the cement and raise soil pH. Another consideration when choosing a site for your azalea is proximity to a butternut or any other member of the walnut family. Plant it at least 50 feet away. These trees secrete juglone, a hormone supposedly toxic to rhododendrons and members of the nightshade family. Prepare the planting hole as you would for any tree or shrub.
Azaleas are shallow-rooted, so dig it no deeper that a foot and twice as wide as the rootball.
If you've bought your azalea from a local nursery then set your plant an inch shallower than it was growing in the pot. Mulch the planted azalea to retain moisture, but avoid heavy mulch, as it will deprive the roots of necessary oxygen. Wood chips make excellent mulch and help keep the pH low. Do not amend the soil other than adjusting for pH. Research has found that adding fertilizers and compost to the planting hole encourages roots to stay in the hole, rather than reaching out for nutrients. This provides a poor support for the plant.