Question
My aunt has a "farmette" that is situated next to a creek.  With the heavy rains we've had in PA the last few days, the creek went over its banks and flooded her horse pasture, which it's done many times in the past.  For the first time ever, this time it took all of the grass and topsoil with the water when it receded.  All that's left is clay.  What would cause this?  And how can she regrow 2.5 acres of grass on clay?

Answer
Brian:

My first thought is to ask whether the creek deposited soil or took plants away.

If the storm deposited soil, you can wait until the grass reappears and/or overseed it to improve the stand.  See if there is grass below the clay.  You may not have to do anything.  Soil carried in a river is usually rich soil.

Second choice, your grass is gone and you need to resew the pasture.  You live in an area where bluegrass and fescue grow well.  I would smooth or regrade, fertilize and sew again, maybe using a drag harrow, also called a section harrow, to scratch seed into the ground lightly without covering it too much.

If the grass is gone, start on this soon.  New grass will take a while to come up and cover.

Best wishes.