How low to cut before grinding?

[Foolrouge]

I have two large cedar stumps and a cherry tree stump which I need to grind down at least 2'. Please see the attached pictures. The cedars both had colonies of carpenter ants in them so the holes you can see go down at least 3' below the top of the stumps.



I was hoping for a little advice on the following questions please
- Is it a good idea to dig down around the stumps some more, power wash the outside of them, and then lower their current height with a chainsaw?
- From a cost saving perspective, if I have the motivation and time, is it worth trying to grind stumps like this out myself with a 13hp Honda Stump grinder or is that a futile exercise?

Thank you in advance for any suggestions!

 

[sean donato]

Honestly, either rent a decent sized/powered grinder for a day or hire a pro in to do it. Those little ones take forever. They look plenty low from what I've seen.

 

[singinwoodwackr]

That isn’t worth the chain to cut those any lower. Just grind um. Go down a good 6” from ground level.

 

[TheJollyLogger]

Whoever designed those 13 horse "grinders" should spend eternity in Hades endlessly trying to grind stumps with them...

 

[SweetMK]

Did you consider burning them,??
I have been able to burn some stumps 8-10 inches into the ground.
Put a barrel over them, they burn like they are in a woodstove.

Stumps that big are like eating an elephant,,
you gotta do a little every day,,,