Looking around town, it's easy to see we live in the high desert. Few homes sport a green lawn. The best manicured spreads feature artful rocks and hardy native cacti and succulents. This is all well and good for ornamental plantings, but what of us that grow a few vegetables or water hungry flowers in our garden? Outside of the too-short monsoon season, these plants need irrigation which isn't always possible with water restrictions.
First, our soil is sandy or rocky. Water drains right through the desert topsoil and is quickly lost. The easiest ways to remedy this is to grow in containers or raised beds. Most water-hungry plants have shallow roots that penetrate no more than 6- to 8-inches into the soil, so a short raised bed suffices. Only use rich soil to ensure it traps that water. If you aren't opposed to the chemicals, soils containing moisture holding gel crystals can further help conserve moisture.
Second, make sure you mulch! Thick layers of straw or wood bark keep that moisture in the soil so it doesn't evaporate away. In a vegetable bed you can stick a piece of plastic beneath the mulch to further prevent water loss.
Finally, water wisely. Use gray water, such as dish water or bath water, to feed flowers and ornamentals. Water in the evening or wee morning hours to minimize evaporation so the moisture can seep deep into the soil. Water slowly, don't flood the plants briefly. Also, consider drip irrigation and avoid overhead watering at all cost.
One interesting way to irrigate in our area is with buried terracotta pots, called ollas. These pots have a fat bottom and narrow opening. You bury the bottom in the bed near the plants you are watering. Fill the pot with water and it slowly seeps through the terracotta and into the soil surrounding nearby roots. They only need filled a couple of times a week and all but stop evaporation.