Quick story of how much I hate ailanthus... A few years ago a large limb fell from this same tree. It came crashing down literally 4 feet from my splitter. I promptly cut it up and threw it over the fence into the woods. I'll never split that stuff, no matter how close it gets to my splitter.
I did it. I heard about it a few years ago so I decided, what better tree to try it on than an ailanthus?
So why didn't you girdle both? I have one of them in my back yard right over my shed and mixed up with an oak. It's pushing 18" DBH and 70'. I wish I was wiser 20 years ago when I bought this house and it wasn't so big. It might have been a clean drop then.
Tree grows very fast,can get quite big in a hurry,very weak soft brittle wood that dries fast/splits easily but it tends to stink,leaves more ash behind than anything I ever burned.In March 2000 I paid a guy to climb/top out 3 of those things on my small property here in town.2 were from 18 to 24 diameter,up to 50 feet tall,biggest ones I ever seen.1 was about 12 diameter & around 30 feet. Nasty effing stuff,the leaves/flowers stink pretty bad,twigs/branches even up to 6-7" are quite brittle & always coming down in wind/ice storms.He topped them out,I chipped up everything up to 3",dropped the trunks then bucked/split everything else.Didnt want to dump the 6-7 pickup loads at parents acreage nor pay to dump at county landfill,so the wood stayed here... 4-5 years later I was still mowing/chopping out those tiny sprouts in the yard.Finally got rid of them.' Never again.Its the only wood I wont cut or bring home.If I see 2 truckloads of the chit on the curb someplace or on CL,it stays put!!!
The tree's a weed, but there's nothing wrong with burning the wood. I burned quite a bit last year & it's not bad shoulder-wood.
It's gotta be the worst smelling wood of all time. Smells like cow chit, but a little worse somehow. And I grew up on a farm, so the smell of cows is like home to me. This smelled awful. And I could smell it from 100' away, maybe more. I had some that was a "mystery wood" roadside score, from the same place I got the Saturn load of black locust. It sat in my driveway split up for about 2 weeks, waiting on my buddy to pick it up for campfire wood. So I borrowed by BIL's truck and delivered it to him. It's THAT bad.
I've heard it is invasive, not native to here. The root system is something fierce and will choke out the native trees trying to grow. As thistle said, its a pita to get rid of.
Some of ours stink like rotten peanut butter. Some have no particular odor. The non-stinking ones will go up the chimney for sure- it is light wood but it gives off heat when it is on fire. I burned a lot of it last year. It remains to be determined what happens with the stinking ones. If the odor abates once dry, they will also go up the chimney.
Back when I lived down there, I'd push them out on the stump and they'd go directly to the burn pile!