Winter Watering is Important

When the landscape looks like this in January, it’s easy to overlook the fact that trees need to be watered in the winter. It’s important to understand that trees don’t go in to total dormancy during the winter. Underneath the New Year’s snow fall, tree roots are actively looking for moisture and this storm did little to hydrate the soil your trees, shrubs and lawn are growing in. Even though deciduous trees appear to be dormant now, their root systems continue to grow and need moisture to survive. You may not see the damage right away, but trees that don’t receive supplemental watering during the winter may experience smaller leaf production, branch dieback and chlorosis through spring and summer. This is especially true of trees planted this past season that haven’t had time to establish. While more mature trees have the advantage of a larger root system to draw moisture from, newly-planted trees need to be watered during the winter to prevent damage and die-back to fine roots. We know it’s important to water trees this time of year. but for winter watering to be effective, there are key factors you need to take into account, including temperature, time of day, and sprinkler type. 

First, pick a day when the ambient temperature is forty degrees or higher and there is no snow on the ground. Plan to water around mid-day, to allow time for the water to soak into the ground.

 Use a soft spray attachment such as adjustable hand-held water nozzle, a simple stationary sprinkler or soaker hose. Don’t turn your sprinkler system on. For deciduous trees, place the sprinkler halfway between the trunk and the dripline.  

How long you run the sprinkler or hose attachment depends on the size of the tree trunk. A good general formula is five minutes per inch of tree diameter. For example, a tree with a three-inch trunk merits fifteen minutes of watering, moving the sprinkler three  times or until you’ve covered the entire area under the tree canopy. A tree with a six-inch diameter trunk would require thirty minutes of watering, moving the sprinkler every five minutes. 

For conifers, follow the same guidelines, placing the sprinkler near or just under the drip line. Since trees don’t lose moisture as rapidly in winter as they do in summer, a deep watering once a month should be sufficient. 

While you’re at, water the lawn.  Turf grass that is well-hydrated through the winter months is more resistant to insect activity, will start to green up earlier in the spring and typically experiences less die-back through summer’s heat.   

Once you’re done watering, be sure to disconnect the hose from the outside faucet.