I decided to use a wood-chip mulch. I don’t believe a mulch is strictly necessary, but I chose to do so for aesthetic reasons because the garden is in a prominent position.
I only put 1-2 inches down, which is less than recommended for most garden projects. However, for a native plant garden, less mulch is more appropriate because in 1-2 years, the plants will create their own “green mulch”. And in the meantime, plants will be able to self-sow because there isn’t much mulch there to stop them.
Thick mulch has the benefit of suppressing weeds. This mulch less so. However, weeds are less visible than they would be on bare soil. Weeding will be an important part of maintenance in the first year.