Can this buckthorn be air-layered?

[August]

While cleaning up the garden a month or so ago I spotted this absolutely huge buckthorn stump growing from underneath a concrete planter.



It would be pretty much impossible to pull it out, so my thought process turned to layering. Be that as it may I have never attempted an air layer, and I only know the bare basics of what the process requires and how it works. Does there need to be more top growth? Is the stump too thick for it to work?

 

[sorce]

If you're interested in laws that may not matter, it could be illegal to propagate it.

Go for it!

Though, I would pass since there must be a thousand more better to dig.

Sorce