TREES: Deciduous trees cause lawns to thin out over the summer since they block most of the photosynthetically active sunlight. Coniferous trees cause lawns to thin out due to the accumulation of debris under the trees, in addition to blocking critical sunlight. Competition from tree roots for water exacerbates lawn problems, as does heavy usage.
WEEDS AND WEED GRASSES: Because lawns in shade tend to thin out over time, they are easily colonized by weeds and weed grasses. Annual Bluegrass is a common pest in shade lawns.
DISEASE: Due to poor air circulation common in shady areas, turf diseases are common in shade lawns.
SOLUTIONS: Thinning , raising the crown and removing weak or problematic trees are great ways to increase light and air circulation. Annual over-seeding will help to keep turf thickened as will minimal fertilization and water applications. Bag all clippings in shady areas. Don’t expect a shade lawn to consist of a uniform stand of grass – oftentimes a blend of tolerant grasses will provide the best solution.
Accept moss and compatible weeds – they will help give shady areas a nice, green appearance.
Choose turf types that are shade tolerant such as Colonial, Creeping or Velvet Bentgrass. Fine Fescue is also an acceptable choice. Perennial Ryegrass and Kentucky Bluegrass are poor choices for shade. Always use seed, not sod, for lawns in shady areas using slit seeding or overcast seeding.
Because shady lawns require additional care, the best option may be to eliminate lawns in the shade and choose an alternate option, such as a shade tolerant groundcover or pavers. poor choices for shade.