  We analyze leptogenesis in a supersymmetric triplet seesaw scenario that
explains the observed neutrino masses, adopting a phenomenological approach
where the decay branching ratios of the triplets and the amount of
CP--violation in its different decay channels are assumed as free parameters.
We find that the solutions of the relevant Boltzmann equations lead to a rich
phenomenology, in particular much more complex compared to the
non--supersymmetric case, mainly due to the presence of an additional Higgs
doublet. Several unexpected and counter--intuitive behaviors emerge from our
analysis: the amount of CP violation in one of the decay channels can prove to
be be irrelevant to the final lepton asymmetry, leading to successful
leptogenesis even in scenarios with a vanishing CP violation in the leptonic
sector; gauge annihilations can be the dominant effect in the determination of
the evolution of the triplet density up to very high values of its mass,
leading anyway to a sizeable final lepton asymmetry, which is also a growing
function of the wash--out parameter K=Gamma_d/H, defined as usual as the ratio
between the triplet decay amplitude Gamma_d and the Hubble constant H; on the
other hand, cancellations in the Boltzmann equations may lead to a vanishing
lepton asymmetry if in one of the decay channels both the branching ratio and
the amount of CP violation are suppressed, but not vanishing. The present
analysis suggests that in the supersymmetric triplet see-saw model successful
leptogenesis can be attained in a wide range of scenarios, provided that an
asymmetry in the decaying triplets can act as a lepton--number reservoir.
