D. auriculata and the closely related D. peltata (they are sometimes considered to be the same species) is one of the easiest tuberous sundews to grow.
I grow my plants in 5 inch deep pots of sand/peat (1:1), during their growth period (for me = November - May approx.) I stand the pots in a tray of water (about an inch, but the level fluctuates) and let the plants get as much sun as possible (not that much in England, in winter). These plants prefer cool temperatures, mine have a min. temp. of 45F (7C) and rarely get much warmer than 70F (20C). I have no idea what temperatures you experience outside in your part of Arizona over winter, but if you remain frost-free you should be OK.
When the above-ground foliage dies back in late spring, I allow the pots to dry out a little (I keep them damp all summer) and place them back on trays of water in sun in autumn (October).
This species (or sub-species), unlike most tuberous dews, is self-fertile and produces plenty of viable seed, which I also sow around October.
Cheers
Vic