Well the time has come to do a little winter watering. We have not had any measurable precipitation in over two months and with warm and breezy conditions the landscape is in need of a little drink. Last year we enjoyed a very strong El Niño condition in the equatorial ocean waters and that helped to provide the second snowiest year in Boulder's history, unfortunately this year there is a very strong La Niña condition. These conditions are caused by either colder than normal equatorial waters or warmer than normal equatorial waters. The change in ocean temperatures have large affects on global weather patterns. You can find more information about these ocean conditions and their affects on NOAA's Web site.
There are always questions about the need for winter watering. I tend to use an anology to help explain the need. If you think about a bear in hibernation, that bear has lowered its heart rate and made other physiological changes to give it the ability to survive without eating or drinking for months on end. Well the reality is that they still use nutrients and water during hibernation but at such a slow rate that they dont need to wake up and eat or drink. Turf and landscape are much the same. During the winter they go through changes that allow for greater uptake of nutrients and moisture to prepair for winter dormancy. Just like the bear, plants don't grow and don't need to be mowed or trimmed, but they are still living organisms that consume nutrients and moisture. They are just consuming them at a much slower rate than during active growing. The difference between the two is that a bear can weigh up to 1000lbs and the crown of a plant like turfgrass is a little larger that the head of a pin. This does not allow for large amounts of storage capacity.
For these reasons, during a stretch of above average temps and below average moisture, we will bring on the irrigation system to give certain areas that are south facing, or have new plants, a good shot of moisture. During the normal summer months, there are irrigation operations that take place very frequently to satisfy the need to replenish lost moisture; however, during the winter months, a good watering on one day could last for weeks before there is need to irrigate again.
Let's hope for some help from Mother Nature!