|How do you plant and what type of grass do you plant under trees?
|Lawn grasses grow best in full sun or with a minimum of a half a day of direct sun. Under trees, there may be excessive shade as well as competition from tree roots that combine to make growing grass difficult. If the area is shady, you may want to consider using a shade tolerant groundcover instead. Your local county extension should be able to help you analyze the growing conditions in the area you want to plant and help you determine if it is suitable for grass or not. They also offer many detailed publications on lawn establishment and lawn care and should be able to give you specific advice with regard to the best lawn grass varieties for your soil and climate along with helping you with some basic soil tests -- you will need to start out with soil testing as the first step toward preparing the soil prior to planting the lawn (or groundcover).
Good luck with your project!