Vegetables Gardening - Growing Organic Vegetables

I'm interested in this discussion because of a situation that occurred in our yard. We moved to our new home several years ago and the previous owner mentioned that she didn't have good luck with the garden. 

We thought we would try to start fresh so we set up the Square Foot Garden method including buying bags of their soil.  It started out well, but as the months wore on things stopped growing and were stunted. 

The production was low and we were pretty frustrated.

The second year was worse. I started hundreds of plants inside that were growing well but as soon as I put them in the garden, they would stop growing. We thought maybe they weren't getting enough water so we stepped up our watering.

An important fact is that we use well water to water it. It's not attached to our home, just to the sprinklers.

Near the end of the growing season I began to wonder if it was the water that was the problem. I took a sample of our water to our local water treatment facility and asked them to check it. Turns out the water is salty. 

We immediately started using our culinary water on the garden and it started to improve. 

It's still not growing very well though and I'm wondering if there is something we can add to the soil to help it be balanced. With so many years of salt water on the soil, is there any hope?

Thanks,

Mindy