There's a film and play based on the tale, "On Borrowed Time." I don't recall the original story title, & certainly it wasn't something that sappy in Russian,
There's also a story called "Tia Miseria" where an old woman traps Death in a pear tree and no one can die until she lets him down... a Spanish/ Hispanic-American story. It's collected in an anthology called "From Sea to Shining Sea."
I know you said you solved this but John Galsworthy wrote a series of short stories called 'the apple tree' which were very readable (like his 'Forthsyth Saga). It seems there is a plethora of apple tree stories to enjoy if you so had the inclination.
Think this might a Russian short story. A little boy traps death in an apple tree and nobody in the world can die. Help...what is it?
Greta