This piece will be about using your sprinkler timer to alleviate the uneven watering some of your zones may be causing. I will also cover how to compensate for a bad system design.
Through the years I have seen a lot of bad sprinkler system designs with little thought behind them. Whether by a builder for cost reasons or a homeowner with a little knowledge, they all are prone to certain problems. The most common of these are lack of proper area separation. These include grass and beds on the same zone as well as sun and shade areas.
Another flaw I see a lot of is having rotors and spray heads on the same zone. All these mistakes are ones that I have even seen professionals make so the inexperienced are not alone in this. Now that one of my pet peeves is out of the way, lets get to how to deal with these problems without redesigning your whole system.
Before continuing I should say that I am biased toward certain brands of products do to my experience so any brands I recommend are only my opinion of the best ones. I am sure there are many who will disagree and there are products I have not run into so use this information as you see fit.
Now on to problem solving. The best thing to have is a timer with enough programs and start times to give you the options you will need. Since there are a lot of cases where the timer has too few options it may be time to upgrade. Both Rain Bird and Hunter have extremely simple to operate timers with multiple programs and start times.
The main reason for multiple programs is that in most cases it is only one or two zones that are a real problem and these need to be separated from the rest of the zones. In all the cases mentioned above the most common result is part of the zone getting too much water while trying to keep the rest green. The best thing to do is move the zone to another program, turn the running time down and use multiple starts. This gives a cycle and soak effect.
Although this is a good practice for all the zones it is not always practical. What this effect does is avoid pooling and runoff allowing the ground time to absorb the water. This also cuts down on the amount of water needed to get the best results.
Since every situation is different these suggestions are for general information and need to be adjusted to your individual problem. While adjusting the times for your sprinklers will help, to get the best results some changes may need to be made to your sprinkler heads as well.
Here is where I need to cover the adjustments that may be needed to your sprinkler heads. In most cases turning off some of the heads in the wettest areas or switching to low flow nozzles like the MP Rotator will do the job. In the case of a mixed zone of rotors and spray heads changing some of the heads completly may be required.
Michale Holmes has been designing and repairing both residential and commercial sprinkler systems for over twenty-five years. As well as having extensive experience in all fields of landscaping from construction to maintenance he is also the author of The Homeowners Guide to Sprinkler Systems which can be found at http://mrhirrigation.com