We have a large Norway Maple - about 40 years old. We are losing the grass under it. Is there something that will help?

Well, sorry to say, you will most likely NEVER get grass to grow under it. Maples have a dense foliage so its really shady, AND, maples roots are water/nutrient hogs. Don't waste time or money trying to grow grass under it... most plants won't even grow under it (you would have to water constantly). Mulch it... that's about it.

I agree, mulching would make the area look better and help the tree. You can try shade grass seed but much of that is an annual seed. I planted Vinca and it looks great.

Vinca is a good idea... you can't kill that stuff! Lol

You're very correct. I has some clover and other weeds get started and it was beyond hand pulling. I sprayed Ortho lawn weed killer directly on the bed and the Vinca did not blink.