Though grass can grow under pine trees, most grasses do not fare well under these conditions. Fescue does best under pines in cooler climates, while zoysia does well in warmer areas. Grass competes with pine trees for sunlight and water. Acidic soil is another problem for most grasses.
To improve the viability of grass under pine trees, several steps can be taken. Prune the tree's upper limbs to increase the availability of sunlight to the grass. Rake the pine needles. Test the soil's pH level. If the pH level is below 6.0, add lime or other alkaline fertilizer. If these methods fail, the area can be mulched or planted with a low-maintenance ground cover.