  LArGe is a GERDA low-background test facility to study novel background
suppression methods in a low-background environment, for future application in
the GERDA experiment. Similar to GERDA, LArGe operates bare germanium detectors
submersed into liquid argon (1 m$^3$, 1.4 tons), which in addition is
instrumented with photomultipliers to detect argon scintillation light. The
scintillation signals are used in anti-coincidence with the germanium detectors
to effectively suppress background events that deposit energy in the liquid
argon. The background suppression efficiency was studied in combination with a
pulse shape discrimination (PSD) technique using a BEGe detector for various
sources, which represent characteristic backgrounds to GERDA. Suppression
factors of a few times $10^3$ have been achieved. First background data of
LArGe with a coaxial HPGe detector (without PSD) yield a background index of
(0.12$-$4.6)$\cdot 10^{-2}$ cts/(keV$\cdot$kg$\cdot$y) (90% C.L.), which is at
the level of GERDA Phase I. Furthermore, for the first time we monitor the
natural $^{42}$Ar abundance (parallel to GERDA), and have indication for the
$2\nu\beta\beta$-decay in natural germanium. These results show the effectivity
of an active liquid argon veto in an ultra-low background environment. As a
consequence, the implementation of a liquid argon veto in GERDA Phase II is
pursued.
