I planted some beautiful rasberries in my yard last year. Summer bearing and ever bearing plants. This last spring we had a very late frost that made all of my plants die back to the ground. They did grow back all over the place! And they have been producing some beautiful berries, but the berries aren't very sweet and I've discovered that the Ph is a bit off.

Currently sitting between 4 and 5.
How can I improve the Ph of my soil and improve the flavor of the berries?
Anyone have any suggestions?
Thanks to all![/b]