Question
I know, I know!!! Tree is taking the sunshine and water.
But I have sprinklers and try to keep it wet.
The grass used to grow pretty decent under the trees. Better than expected, really.
However, it seems that after the recent bumper crop of acorns... the grass won't grow.... even in the most favorable areas with some sun. And the farther out places are having problems now.
The grass usually dies or turns yellow and mushy(it looks like it drowned).
I would like to get it back a little and don't expect a lot. Just a little closer to a few yrs ago when it grew pretty decent.
Can I put down lime? Would you recommend anything else? My friend said Gypsum would help...... but research tells me that it is only good at loosening up our black clay soil in N. Texas.
Vigoro fertilizers seem to help.... and i get a few runners who strike off towards the bare spots. But it is much more thin than previous yrs.
Maybe it needs food?

Thanks for your time. I am a fellow expert and though I would try out this service for myself. LOL

Tom

Answer
Can we assume this Oak is NOT a Black Oak?  Because if it is, you can forget about growing everything there except more of the Black Oak thanks to juglones (those repulsive chemicals oozed by certain plant roots that don't like to share).

Let's start with your Oak Tree-Grass Competition.  When the Lord made Oak Trees, He did not want us to grow grass under them.  Oaks and other trees need groundcovers and mulch.  Not grass.

Anything you plant under them, right up to the drip line, maybe further, will be competing with the Oak Trees for nutrients, water, air and light.  Any vitamins and minerals you give your grass under there will be used by the Oak Tree.  No grass stands a chance.

Show me an Oak Tree with thick, green grass at its base and I'll show you a can of green paint in the garage.

Grow something else there.  And don't forget the Bird Feeder and the Birdbath.  Don't believe me?  I'd like to know if there are any Weeds growing under the Tree.  Weeds can almost grow anywhere... almost.

Fertilizer is not going to make it happen, either.  Those big old Oak roots are very powerful.  They will take up anything you put down, way ahead of the Grass.  With one exception:

www.laspilitas.com/plants/1404.htm

Elymus condensatus (aka Lymus aka 'Giant Wild Rye').  'It will grow well in full shade with no extra water.'  Not a Grass you date for its looks, but it is at least on that short list of choices that can endure the life of a green plant growing in the shade of an Oak.

I wish I could be more optimistic here.  You are not alone.  I push for Pachysandra and/or Hostas for best results.  Or a thick mulch and a tree swing.  Maybe in the future.  But not alas in 2008.  Thanks for writing -- keep in touch.