  Studies of the clustering of the most distant Kuiper belt objects in the
outer solar system have hinted at the possible existence of a planet beyond
Neptune referred to as Planet Nine (P9). Recent efforts have constrained the
parameter space of the orbital elements of P9, allowing for the creation of a
synthetic catalog of hypothetical P9s. By examining the potential recovery of
such a catalog within numerous sky surveys, it is possible to further constrain
the parameter space for P9, providing direction for a more targeted search. We
examine the ability of the full six years of the Dark Energy Survey (DES) to
recover a synthetic Planet Nine population presented in Brown and Batygin
(2021a) [arXiv:2108.09868]. We find that out of 100,000 simulated objects,
11,709 cross the wide DES survey footprint of which 10,187 (87.0%) are
recovered. This rules out an additional 5% of the parameter space after
accounting for Planets Nine that would have been detected by both the Zwicky
Transient Facility and DES.
