How high should my dirt be around sidewalk?

I’ve been slowly replacing my lawn with native plants and food and I’ve come to the area on either side of my sidewalk. I’m planning to plant native bulbs in the treelawn this fall, and turn this patch in the front yard into an herb garden. The sidewalk is a few inches below the ground on either side. Sometimes we have water pooling there. Last year I dug a few small ditches through the treelawn to help drain that water to the street.

I’m looking for advice on the ideal height for the dirt. I’m thinking I should remove a lot of the dirt from the tree lawn to bring it down level to the sidewalk. For the front yard, I’d use the same paving stones you see in the background as a border between the sidewalk and front yard to make up for the different in height.

by Elegant_Purple9410