pitchpine
Mame
Were I in your shoes, I would be looking around for other volunteers.
....
Regardless of how it works out, there will be a lot for uncle and niece to talk about for many years.
No other horse chestnut volunteers currently, but I am thinking about trying tomorrow to collect an American elm that's been growing along my parents' fence for pretty close to my entire life. It's been hacked back so much that it's got a pretty decent base; the question will be whether I can manage to excavate it from the fence!
Oh, and I'm an aunt, not an uncle, but otherwise your last sentence is spot on!

Laura