Warning: probably too much information in this post.  There are many variables that come into choosing drip settings, but my observation is that the vast majority of people water too frequently and not deeply enough. Deep watering has two good results: it wastes less water and encourages stronger root development, making plants more drought and cold tolerant. Some of the variables to keep in mind include type of soil (clay retains water better than fast draining soil), how new the shrub/tree is (first summer requires about 150-200% of the water for a same sized established plant), how many emitters are on the given shrub/tree, and how fast flowing the emitter is (they are rated in gallons per hour, with common values of 1/2, 1, 2, and 4...some varaible emitters I have go to 5 or even 8). This may be useful for your backyard that is on the same zone, as you can still apply more (or less) water by using different rate emitters. I'll describe what I do as a possible guideline...it has worked well for me. I have three zones - a lawn and flower garden zone (pop-ups), a moderate use zone (drip), and a low use zone (drip). None of my cacti are on drip. Also note that most of my trees/plants have made it through at least one summer, some two. i.e. I've cut back a little comapred to first summer plants. Currently, I am watering the lawn zone twice a week for 20 minutes. This might be a little too much actually. The moderate use is run once a week for 3:00, and the low use is run once a week for 2:15. In general, the low use has slower flowing emtters, too. In a couple of weeks I may add a second running for the moderate use for about 30-45 minutes sicne I have potted plants on it. Examples of what I have on each zone: moderate use: hibiscus, roses, heavenly bamboo, orange jubilee, passion flower vine, pink trumpet vine, butterfly bush, arizona sweet orange tree, several potted plants on the north side of the house. Low use: desert willow, shoestring acacia, cape honeysuckle, bouganvilliea, spotted emu, pyracantha, texas sage, mexican bird of paradise, yellow bird of paradise, hummingbird mint, angelita daisy, blackfoot daisy. Trees and large shrubs should have multiple emitters. As they grow, new emitters should be added, and they should be moved to the drip-line of the tree to encourage root growth (though keep one or two inside the drip line too. Desert trees like palo verde or mesquite can likely be removed from drip altogether after 3 or so years, but will need a couple of good soakings with the hose in the summer to insure they do not drop leaves. This helps keep their growth in control and reduces pruning needed. This last winter, I completely turned off the drip system from late November through mid February, with one exception (I ran it one time). It is important to cut back on water beginning in October. If it stays warm and you keep high levels of water, you encourage too much new growth that will be much more subject to die-back in freezing weather. As for the cacti...cacti like Saguaro, cholla, and hedgehogs only really need to be watered once or twice 2 weeks after planting, and in subsequent years perhaps once or twice in the hottest/driest parts of the summer. Most cacti should never be watered in winter as they are very susceptable to root rot. Golden Barrel cacti do need a little more water than some cacti, they need to be watered weekly first spring-fall, and every 10-14 days in subsequent years (assuming heavy clay soil). Hope this helps. You might try googling the U of A extension which has detailed watering schedules and descriptions. Also, visit Maricopa Mountain Plumbing, and they are very helpful and may have a free brochure or two. |