Question
Marc, none of the shrub experts is in so you're getting this question-- hope you don't mind.  My MIL lives in zone 5 OH, in the CLeveland area.  She would like to know when is the best time of year for her to plant a pair of hollies by my late FIL's grave? The soil is rather hard and dry in the summer-- should we add anything to it?

Thaks for any help you can give us.  

Answer
Generally, its good to plant in the Spring or the Fall, before 1st frost.  Holly is generally evergreen (but there are a few deciduous varieties still grown in the midwest), It slows its growth in the winter, and has a flush of growth in the Spring.  Planting in the summer would not be the best time.

If the soil is a concern, you can oversize the hole, and add commerical soil mix with the native soil, at about about 50:50. Holly generally prefer rich, slightly acid soil, that is well-drained.  I'd also add some mulch to the top of the root area, after planting.

Not mulch else, I can think of, to help!