The Last Mowing Session of the Year

A couple of weeks ago during the warm spell, I finished mowing the yard for the last time this year.  I was mowing the back yard with about 3 minutes left to go when I hit something with the mower deck.  I should say I hit something BIG with the mower deck, for all the guards shuttered off, and of course it sounded just terrible. 

It turns out that my Number 2 Kiddo planted a landscape rock in the yard, and it was beneath some maple leaves.  It was a huge rock - the size of 2 fists put together. 

I finished up my last 3 minutes of mowing, and pulled the deck off to inspect the blades.  They were in pretty bad shape.  This one is the worst - pretty big chunks out of the entire length of the cutting surface:

 

 This blade was pretty bad, too.  It had a nice chunk missing from the tippy tip:

And here is my guilty boy with the rock that did all the damage.  I'm not sure why the rock doesn't look worse.  And I'm not sure why the boy is making such an odd face.

 

I'm leaning towards buying new mowing blades, for grinding out that much metal will really be taxing.  I have the winter to think about it though.