JoAnne Skelly: The irrigation dilemma

It’s the annual conundrum. Is it too soon to turn off the irrigation system? With recent nights down to the teens here in Washoe Valley, we turned off the irrigation system and drained it prior to the hard freezes. Then we turned off the outside water and drained the hose bibs too. Yet with temperatures back in the 60s with low to mid-30s at night, I’m sure I will have to irrigate again soon.

Trees can’t go the rest of fall or through the winter without water, especially when the temperatures are mild and the days are sunny. While only evergreen trees lose water through their needles (their leaves) all winter, both they and the leafless deciduous trees need their roots hydrated to survive the winter. We are probably in for quite a dry winter this year unless the expected La Niña is kind to us, which is unlikely.

To water again I will either have to close all the in-ground drains for the sprinklers, turn the system back on and then re-winterize it, or drag hoses to every tree. It’s a pain, but every year I do it, because I love my trees!

Prepare your plants, particularly trees, for the probable dry season by watering deeply on a moderate day. Then, watch the weather reports. When hard freezes are expected (below 28 degrees), turn off the irrigation system and winterize it. If, or I should say when, there are prolonged dry periods of three weeks to a month, turn your irrigation system back on and water deeply again.

The lawn, unless it’s newly planted this year, will be fine. However, if you don’t want to re-winterize your irrigation system each time you water, drag hoses and sprinklers around to each tree, rose bush and any newly planted shrubs as I do.

Be sure to drain the hoses when irrigation is completed, disconnect the sprinklers, turn off your outside water and drain the hose bibs. That’s winter plant maintenance in an arid environment.

Here is a correction to my garlic article. My friend Arnold Carbone of Glorious Garlic Farm pointed out “Your method for when to harvest is more for onions. Harvesting garlic is an art that depends a lot on observation and weather conditions. The plants should always have some green leaves on them before you harvest.” Arnold says “When the garlic leaves begin to turn yellow in the summer, stop irrigating for two weeks and then pull up the plant. Immediately place plants in a shady place to cure.”

JoAnne Skelly is associate professor & extension educator emerita University of Nevada Cooperative Extension.