I have quite a few iron stains (red streaking spots) in my driveway from a fertilizer application gone bad.

I tried some driveway cleaner that had a mild acid in it and it didn't do much to remove the stains, only leaving large bleached looking spots over the iron stains. I have two questions:

1. What is the best/safest way to remove iron stains...preferably something that will not kill foliage.

2. Will the large white spots (acid stains) from the cleaner I used fade over time or is there any way to remove them quickly?

Thanks...