Given the situation and the need to bring in soil I would strongly consider something with shallow roots perhaps blueberries as they need specific soil conditions and with a ph of 4.5 to 5.5

Put citrus trees there.

I have a bunch of yard dirt I’m grading, it could be used to fill some of the bed. Is a raised bed on gravel and concrete similar to a pot, where this would be a bad idea and I must use professional potting soil?

A raised bed is much more like in ground planting than container planting. Use a standard truck load of topsoil.

Steve

If the bottom surface is concrete or gravel, raised bed will act like a container. To act like in ground bed the texture of the soil above and below have to be similar.

OK thanks guys. I talked with my wife a bit more today, and she has (justifiably) changed her mind and would prefer if I just use pots for now. Still a good location for citrus.

1. A 2 foot tall sheet of plastic 12 .2 feet long joined on the ends and put on the ground make a 4 foot diameter pot that is 2 feet deep. This can be done with chicken wire lined with weed barrier.. Cheapest pot you will ever find. Every 3 years unwrap it, root prune, reinstall it, and add dirt. This will be the easiest root pruning job you ever had.
2. Steve

That’s a good idea, as long as you don’t need to move it and appearance is not a big deal.

[Read Trianglejohn's input[(https://www.houzz.com/discussions/do-you-root-prune-keep-potting-up-or-do-nothing-dsvw-vd~1837318?n=29)

Steve

Interesting stuff

Parking lot beds contain whatever pollutants vehicles have been known to generate. Including asbestos from break linings, lead from leaded fuels, and used motor oil washing into them where surface drainage is not adequate. As well as being used as receptacles for various kinds of litter. Such as - in this case - construction debris. They can also have a history of herbicide applications and the pooping of dogs (or sometimes humans).