The Reno climate really makes it difficult to answer the question "when is the appropriate time to activate the irrigation system." Although Reno's climate promotes the grass to go dormant during the winter, the lack of rain and snow this winter, along with warmer temperatures, has people wondering when they should activate their water. Truthfully, there is no single answer to this question. However, depending on what type of person you are, there are a fe suggestions as to when you want to activate your water.
Early Activation (3/20-4/10)
This time is usually when most lawn care companies will activate their water, for both commercial and residential sites. This is normally done at this time because faster growing grass means mowing can be done sooner, which equals more money. At this point in time, the weather should be done with the hard frost, the ground should have thawed out, and freezing pipes SHOULD be out of the question. However, there is still a chance that a really cold night could leave you with a cracked pipe in the morning. If you want to be the first person on the block with a green lawn and believe this is better than possibly having a cracked pipe - then go for it, just be aware of the possible repercussions.
Mid-Season Activation (4/10-4/30)
This is the point in time where most people probably activate the irrigation system. Although you will not be the first on the block with the green lawn, you won't be the last. During this period, observe when the forecast no longer shows sporadic nights in the 20's, then have the piece of mind that nothing will break in the night. By waiting this long you have saved on your water bill for just a bit longer, and no damage has been done to the grass or the irrigation system. The downfall of waiting until this point is that many companies have already started to aerate, and if your lawn has not had a good soaking before the aeration process you might not get good cores out of your lawn. For more information about this, check out Lawn Aeration Part 2.
Late Season Activation ( 5/1- 5/20)
Unfortunately, the downside to waiting this long is that you will most likely be the last person on the block to have a green lawn, and after a winter like we just had this might be pushing the sustainable drought period of your lawn. The only benefit in waiting till this time is the amount of money you will be saving on your water bill. However, a period of drought for you lawn may actually encourage the roots in the lawn to grow deeper, as they try and find water further down in the soil. This is a good thing. Just make sure that you are not stressing your lawn out too much if no amount of rain has accumulated throughout the previous months.
Ultimately, you want to decide what type of person you are when it comes to activating your irrigation. Weigh out the pros and cons to these time periods, and figure out what works best for you and your property.