i used to swear by a strong Round up solution
and even bought four gallons of the poison Ivy specific
round up and it didn't kill it....in some spots
you have to have four consecutive days of sunshine
following a spraying regimen for the systemic to work
but since then i have switched over to smothering it
and will used 6 mil black plastic from now on
in a large area , and use piles of OAK leaves that contain
Tanic acid that kills out stuff fairly well and/ or a combination
of all three..... you basically have to declare WAR