The Bogard surname may be a variant of Bogart, which is derived from the Dutch surname Bogaert or Bogaart. These are archaic spellings of the modern "boomgaard", which means "orchard". [1]
But at least some Bogards may have roots in the Jewish family name Bogorad / Bograd. The two surnames could have been confused by western officials, or even by family members, or could have been deliberately switched to conceal Jewish origins.