Is it a good idea to add compost when planting trees or shrubs?
Yes. Compost will add moisture holding capacity to the soil as well as let air get to the roots. Not to mention the availability of nutrients. When planting, dig a hole twice as large and deep as the root ball. Fill the hole back to the proper depth with compost and the rest with a mix or what was dug out of the hole (if it is good) and compost. Using this method will allow the roots to stretch out and grow quickly.