I put $70 worth of rye seed down all over spillway and dam after the pond was built. The dam had top soil spread on it and the rye and weeds sprouted very quickly over the summer. My spillway however is pure clay and I would say 50% of the rye sprouted. What can I do to help promote grass growth without hurting the pond. I wanted to put fertilizer down, but do not want to hurt the water quality with run off.

Any info would be much appreciated.

I would add aglime instead of fertilizer. Nothing grew on my clay until I limed it.

I had a spillway but we wanted to drive over it so I installed 2 24” culverts and built it up and ended that problem

Neighbor added limestone rock to keep the wash down and the lime from the rock seemed to allow grass to grow and root

Pure clay is hard to grow things on. Without sending a sample in and having it tested for N-P-K and pH, anything I saw would be a guess.