Mine is still quite young, but it seems to do fine with full sun until noon and again from 5pm to sundown. And that is in my zone 7a, Mid-Atlantic area...so your zone 4 sunshine would probably be no problem. :)

split it in half.. and put one in sun.. and one elsewhere ... and then tell us the result ...

ken

Ken, oh dear Ken.
Lest you forget.... some of us do not have the room you do to trial stuff out. I don't have room for 2 of anything!