Winter watering

Do you need to water the landscape in your yard during the winter? Absolutely yes! Just because some of your trees, shrubs and turf may look dead, they are not. They are dormant. Big difference.

I liken dormancy to when we sleep -- an analogy that would probably make my plant physiology professor cringe. There are still activities going on in our bodies while we slumber. We don’t temporarily die each night then wake up alive again the next day. There are two types of dormancy with woody plants. To learn more, read this online article by Michigan State University Extension: http://msue.anr.msu.edu/news/winter_dormancy_and_chilling_in_woody_plants.

Our average annual precipitation in this area is around 14 inches. Hailing from northeast Oklahoma where we average over 40 inches annually, the climate here was quite the shock. Unfortunately, for the past two years we are even drier -- accumulating just under 12 inches of precipitation annually. If you have lived here long enough, I am sure you have heard we are in the high desert. Well, technically we are semi-arid but if the precipitation continues to wane, we may be bone dry desert in the not so distant future.

When my husband and I first moved here, I could not wrap my head around the fact that the Denver metro area receives almost five feet of snow every year. How could we only get 12-14 inches of precipitation when we get nearly 60 inches of snow? I have since learned from weather enthusiasts that it depends on the snow ratio. If you are shoveling your sidewalks, you will likely have noticed that some snow -- the light, fluffy kind – results in less back breaking effort to remove. On the flip side, if you are into making snowmen, then the powder will leave you frustrated because you need the heavy, wet stuff for your creations.

The University of Wisconsin discusses snow ratios and states they can range from 9:1 to 15:1. This means you could have anywhere from nine to 15 inches of snow that results in one inch of precipitation. http://sanders.math.uwm.edu/cgi-bin-snowratio/sr_intro.pl.

Since we have determined our plants aren’t dead and our climate is quite dry, let’s look at some information on supplemental watering during the winter. Colorado State University Extension notes that adding supplemental water to your landscape in the winter can help prevent root damage. They also remind us that “affected plants may appear perfectly normal and resume growth in the spring” but that those plants “may be weakened and all or parts may die in late spring or summer when temperatures rise”. They have a detailed Fall and Winter Watering fact sheet here: http://extension.colostate.edu/topic-areas/yard-garden/fall-and-winter-watering-7-211/.

Basically, moist soil provides a better insulating barrier than dry soil. Water only when the temperatures are above 40 degrees and do so during the middle of the day. Never water when snow is on the ground.

For detailed instructions on the number of gallons needed per tree diameter, check out the CSU Extension fact sheet mentioned above or this PlantTalk Colorado information sheet: http://planttalk.colostate.edu/topics/trees-shrubs-vines/1751-fall-winter-watering-drought/.

Remember to water the entire drip line of large established trees. Their root systems are typically spread out to an amount equal to or greater than the height of the tree. A healthy plant is its own best defense against insect and disease issues, so water regularly during the winter to have happy plants in the summer.

Kelley Rawlsky has an M.S. in horticulture and is the director of Bringing People and Plants Together, an organization dedicated to bringing horticulture education and therapy to the community. For more information: PeopleAndPlantsTogether@gmail.com or follow us on Facebook.