Grass lawns by nature need lots of sun. Kentucky Bluegrass, Perennial Ryegrass and Perennial Fescue are the three most common types of grasses on Minnesota lawns. All three are classified as “full sun” meaning they require a minimum of 6 hours of direct sunlight each day.
Over the years, seed companies have created different hybrids of all three that will survive and grow without full sun that are classified as “shady” or “partial sun” mixtures claiming they will grow in those shade areas of your landscape, but even these varieties will still require at least 3-5 hours of direct sun. In some circumstances this may be the case, however, there are other factors that also need consideration.
Of these, some of the most impactful are morning vs. afternoon sun as well as availability of air movement. Implementation of a good fertilizer and weed control program can go a long way to help improve lawns in these areas. However, grass growing beneath a row of 50 year old maple trees is not likely to fully grow.