groovy!
I've used vinegar but using phosphoric acid makes sense to add some phosphate to the soil. I've hear of people using sulfuric acid as well.
Your garden looks great!
After all the rain we've had, ours is doing well. The cherries, apples, and peaches survived the Mother's day cold snap (32.5 degrees) and the fruits are swelling quickly. The bee hives need new boxes. They've been very busy on the raspberries. More salad stuff than we'll ever eat.