Question
I have a lawn that is slowly dying off in areas that are under trees or in shade all day.  It seems moss begins to grow and out-competes the grass in the spring.  By summer, large patches of soil is exposed and develops large cracks.  I find that the summer after a bumper crop of apples destroys the grass under the apple tree and after a bummer crop of acorns damages the grass under the oak trees - I think it is because the squirrels digging into the lawn destroying the grass.  This process has been occuring over the past 5 years.  I have a combination of 60-80 year old oaks and sassafras and 18-25 year old apple, maple, and dogwoods.  I live in a clay soil area in southern Ohio.  I have tried overseeding and watering to no avail.  Advice?  Help me save my lawn.  

Thanks,
Stephen Balek

Answer
Growing grass in the shade from mature trees can be extremely challenging.

I recommend loosening the top few inches of soil in bare areas and mixing in some compost (available in bulk from topsoil suppliers). Plant a mixture of shade tolorant TALL FESCUE (it is going to be your best bet).

During seed establishment, water frequently and shallowly such as 2-3 times per day for 10 minutes at a time. The goal is to keep the top 1" of soil consistently hydrated.

Once the grass has sprouted and is 3-4" tall, mow it and then gradually change to an infrequent but deep watering pattern such as watering once or twice per week for 2 hours during each application. This watering pattern is the recommended for a mature lawn. Water every week without fail in late spring and summer as the mature trees are competiting for moisture.

If you water infrequently and deeply the top few inches of soil can dry out and that will help keep moss at bay. This being said, if the shade is too deep, grass will not grow and moss will prevail. Only option would be to open up the canopy or remove individual trees. I think, however, with infrequent and deep watering patterns on a good quality soil (w/compost incorporated) that tall fescue in particular can do well.

Establishing grass under mature trees can be extremely challenging and sometimes we have to give up and look for alternatives (shade tolorant ground covers like patchysandra, ivy, vinca, etc).