Winter Watering: Is It Necessary? Debunking the Myth of Dormancy
The Big Misconception: Are Trees Really “Asleep” in Winter?
The Myth: Homeowners often assume that once the leaves drop or the snow falls, the tree’s roots stop working, and therefore no supplemental watering is needed.
The Arborist’s Truth: While deciduous trees (those that lose their leaves) enter a period of dormancy above ground, their root systems are not dormant. Tree roots remain active in the soil, gathering nutrients and, most importantly, absorbing water as long as the ground isn’t frozen solid.
The Danger: Cold, dry air and persistent winter winds constantly pull moisture out of the tree. If the roots can’t find water in dry soil, the tree quickly becomes dehydrated.
The Most Vulnerable: Evergreens and New Trees
Two categories of trees at the highest risk for winter drought stress (often called “winter burn” or “desiccation”).
1. The Evergreens (The Thirsty Trees)
Why they need winter watering: Evergreens (Pines, Spruces, Firs, Arborvitae, etc.) keep their needles and continue to lose water through a process called transpiration, even in winter.
The Visual Damage: When water loss exceeds water uptake, the needles turn brown and brittle—often not showing up until late winter or early spring. This is severe and sometimes fatal damage that could have been prevented.
Expert Tip: Strong winter winds accelerate this moisture loss, making trees in exposed areas critically dependent on soil moisture.
2. The Newly Planted Trees (The Small Root Systems)
Why they need water: A newly planted tree (one planted in the last 1–3 years) has a very small, restricted root ball that hasn’t grown far into the surrounding soil.
Limited Reserves: They have limited access to the moisture reserves of the native soil, making them highly susceptible to drying out during long dry spells. Lack of winter water is the leading cause of death for newly planted trees.
Our Service Note: This is why we stress professional planting and offer establishment care packages!
Our Arborist Guidelines: When & How to Water
| Guideline | What to Do | Why It Matters |
| Check the Temperature | Only water when the air temperature is above 40*F. | Watering on frozen ground is ineffective—the water runs off and cannot soak into the soil. |
| Time Your Watering | Water during the mid-day (10 AM to 2 PM). | This allows the water to soak in deeply before nightfall and freezing temperatures return. |
| Frequency | In dry periods (no significant rain or snow for 3–4 weeks), aim to water once or twice a month. | This prevents root dehydration without risking root rot from overwatering. |
| Water Deeply & Slowly | Use a soaker hose, a drip system, or a slow trickle from a regular hose near the drip line (the area under the outer edge of the branches). | Slow watering ensures the moisture soaks 8-12 inches deep into the soil where the feeder roots are, rather than running off. |
| Apply Mulch | Maintain a 2-4 inch layer of mulch around the tree, keeping it a few inches away from the trunk. | Mulch insulates the roots, holds existing moisture in the soil, and helps prevent damaging freeze/thaw cycles. |
Let Us Set Up Your Trees for a Successful Spring
Not sure if your newly planted Maple or established Blue Spruce is getting enough water? Winter watering is more than just turning on a hose; it’s about checking the soil, applying the right amount, and targeting the crucial feeder roots. For more information, please take a look at our Plant Healthcare Services.
Contact Arbor Doctor Tree Service today at (720) 298-7279 or use our FREE ESTIMATE form for a Winter Health Check. We can assess your soil moisture, identify high-risk trees, and advise on the precise winter watering plan your landscape needs to thrive next spring!
