Did you even realize that blackeberries grow here in Maricopa County? They grow prolifically! The varieties that grow best here are: Rosborough, Womack and Brison. Rosborough are the heaviest producer according to the County Extension Service. Baker's Nursery in Phoenix even has thorneless berries.
Fertilize about 1 month after planting then again in June/July. In succeeding years apply it in March and then in late July. Use a 13-13-13 or 10-10-10, within 2-3 foot circle around the base of the cane. They need to be pruned regularly since the canes that give fruit on year die off but by then new canes have spread so you will have a constant harvest after the first year.
Birds are really the only pest you have to deal with and netting takes care of them during the fruiting season.
For more information on blackberries check with the Maricopa County Cooperative Extension Service. You can down load instructions from your computer.
I have one bush on a trellis and one growing over an arch in the garden. I get many berries for about 1 1/2 months starting in late April and into May. I love to make jam or just freeze them on a cookie sheet then bag them up to use in desserts or frozen fruit smoothies.
Blackberries are a fun new crop to consider growing in your gardens.