Put an old chain on the chainsaw and then cut slots down vertically into the stump. The old chain is so it doesn't matter much if you hit some dirt with it.
Once you have slots cut into it, it can break up or burn easier.
If you bury them stumps, just be prepared for one big sink hole twenty or so years down the road when they decompose. Lot's of folks around here buried their stumps with an excavator and then wonder why there's a big hole opening up in their backyard that just gets bigger every year.
Aloha, Williwaw:
That gives more pukas for future stumps 😀
People buried a lot of stuff after Hurricane Iniki in 1992. Now we see a lot of sink holes here and there after 22 years.
I've had stumps heaped carefully with an excavator, fired up and if stacked properly they gradually fall in on themselves. Eventually they'll need pulling together and off they go again.
Elms! They are notoriously hard to burn. Well the English ones we have here.
I had a bonfire in the yard a few years back. It burnt down to a small heap that I scraped together and left.
A few weeks later I got up one morning to see Smoke rising from the ground. I grabbed the hose as it was summer and fire danger period had set in. The water just disappeared with huge amount steam.
I grabbed a shovel and dug out a huge hole where an old (buried) stump remained.
We've had some old buried stumps and logs causing issues on farms here when they've caught fire in high fire danger periods. Very unpleasant and dangerous to boot.
Seekout Dumbassss Suburbanites
They will buy those things from you if you will just clean them up a bit by removing all the dirt. People like to stick them in their front yards, especially in the middle of flower beds. The turn them sideways and position various things, artistically, around the various root branches. While you are at it, sell them some of the biggest rocks you can find that you don't want any more. Suckerzzzzzzzzzzzzzz!
Seekout Dumbassss Suburbanites
How about talking to the folks at your local "Smoke House"(meats that is). Them boys are always looking for wood to burn.
Try one of these.
http://www.npr.org/blogs/krulwich/2014/07/02/327243804/watch-it-swallow-an-entire-tree-in-seconds
