Berry disappointing

I love home grown strawberries, which taste so much sweeter than store-bought ones. But our climate isn't the best for them, so we never get more than a few each season. I picked (and ate) six today.

As far as other berries go, blackberries are the ones most suited for our climate but even then getting edible fruit is a challenge. Unlike blueberries and raspberries, which prefer a more acid soil than I can provide with any amount of amendments, blackberry canes thrive to the point of being invasive. We bought one plant when we first put in the raised beds, and I later realized that putting them in the same bed with asparagus and roses was a mistake, so I dug them up (or so I thought) and transplanted them to three different places where they would have more room. Not only are the transplanted plants growing and spreading, blackberry canes continue to pop up in various locations in the original bed.

Unfortunately their vigorous vegetative growth has not led to an abundance of tasty fruit. They have no problem setting fruit, as you can see in the picture on the right, but unfortunately the berries sublimate from an unripe and sour red to a dessicated brown, bypassing the juicy, sweet black stage I was anticipating. I did a little research via my friend Google and found the problem might be caused by (a) too little water or (b) too much sun. Shading is suggested, and I haven't done that. I also haven't given them extra water during flowering and fruiting time, because the leaves haven't shown any signs of water stress.

If you're interested in growing berries in the desert, here are some links for further information:

Phoenix Permaculture Alliance thread on growing strawberries
UA Cooperative Extension publication on growing blackberries
UA Cooperative Extension publication on growing fruits in the low desert (Scroll down to the very bottom to see recommended varieties of strawberries and blackberries)