PlantLife Online

Answer

Unfortunately you're going to have a hard time getting any ground-covers to grow under most conifers. The dry conditions and accumulation of leaf litter and needle debris under conifers create a very acidic environment making it hard to establish new plants. Additionally the lack of sunlight year round will inhibit growth as well, plants may only thrive along the outskirts of the canopy.

For best results find ground-covers that thrive in acidic soil conditions. Hard to say which plants exactly without knowing your zone but your local nursery will carry only the evergreen ground-covers hardy in your area. Prepare the site by removing some of the debris and adding a good humus-rich organic matter. Once the young plants have been planted be sure to keep the site moist during times with little precipitation. Due to competition with the tree for essential nutrients, moister and sunlight additional care may be needed to keep the plants healthy.

Fall is a good time to establish ground-covers.

Happy Gardening!