Do Trees Need Water in Winter?
This is a question that literally drives me nuts, especially since I live in a very dry climate with little, to no, moisture through the majority of the year – and yet have over two dozen trees planted around the property. In the summer I keep everything well watered with in-ground sprinkler and soaker systems, but by the time things begin to cool down, my water usage becomes less and less, until I’m not using it at all. Yet, it’s still well above freezing outside.
My tree and shrubs look fine, right? They are still green and healthy looking, and, I mean, nobody is dragging a hose out to the forest are they? And THOSE trees are doing just great year round only with what nature provides them, year after year, whether they are young saplings, or old giants. What’s so different about those trees compared to mine?
But what it really comes down to in asking, “do you water trees in winter?” is understanding how trees work and utilize water in any season, and what you can do to help keep your trees healthy and stress free in any climate.
What Do Trees Do in Winter?
As temperatures begin to drop, trees enter into a dormancy stage in which the life giving nutrients from the roots are no long sent into the canopy for further growth, but rather all the food collected via the leaves (through the process of photosynthesis) are sent into the roots for storage and growth. There have been many studies into trees and their root capacities during all seasons, but much information is marred by the fact that they are hidden away underground year round and are difficult to study without altering their natural environment.
Despite this, roots optimal growing conditions are between approximately 32 and 41 degrees, with a dormancy stage at lower temps as low as 20 degrees, after which death and necropsy begins. This means that below the surface of the soil, tree roots are growing as the temperature begins to drop, and growing roots need water to do so in optimal conditions. Of course, soils hold moisture below ground, and frozen and snow covered soils will leach a certain amount of moisture into the ground as well in the winter months, even in arid conditions due to plant’s adaptability to reach their roots even deeper for moisture.
Through fall continue your watering schedule through your fist freeze, and then give a deep watering once a month in arid, or warmer climates where there is no hard ground freeze, and low snowfalls.
New and Young Trees
If you have newly planted trees within the last three years, then you need to be sure to keep them on a regular watering schedule. On average, young trees need the equivalent of one inch of rainfall through the summer months, and well watered right before the ground freezes come late fall/winter.
If your winter is mild, or particularly dry, provide a good watering at least once a month to allow moisture to reach the roots. Mulching around your young trees in the winter also will help them retain moisture , but be sure to pull it back from the trunk as soon as it begins to thaw to keep any rot or unnecessary dampness from seeping into the trunk itself.
Through the first three to four years you will want to keep soils surrounding fruit trees slightly moistened (light watering approximately once every two weeks should suffice) throughout the entire year. Once the weather warms come spring water deeply and slowly to get moisture as deep as you can without pooling the water, and thus cutting off essential oxygen to the roots. Proper moisture is a must not only for young trees to get established and put forth new growth, but fruit trees need it for good fruit bud set and early production as well.
Watch for sign of water stress going into fall and before full dormancy. Also check moisture depth up to ten inches deep by pulling back soils with a shovel approximately six inches from the base of the tree trunk, especially in mild climates.
Native Trees versus Non-Native Species
Depending on your tree choices, you’ll want to make sure you know if your tree grows as a native of the area, and what its climate preferences are. Despite claims that all non-native trees are considered pests or invasive in certain areas, with proper care most provide good variety and diversity for the pollinators and critters of the area.
There is a difference, however in non-native and true invasive species, so be sure to do your homework considering what would happen if your particular species were to be allowed to grow wild. If it is a threat to the area, then you will want to reconsider your choices.
example of Native trees
example of Non-Native Species
Well established native trees will need little to no watering care during the winter as long as they have grown well during the summer and do not seem stressed. Trees not native to the area may need some extra care past their first few years of initial establishment, and you will want to make sure that good water is provided through both the growing season, and periodically through the winter as well to give it the best chance for further growth come spring.
Deciduous Trees versus Coniferous Trees
Since leaves are a major source of water loss, most trees drop their ‘greenery’ once the weather begins to chill in order to retain much needed moisture through the winter. Deciduous trees are defined by their complete loss of leaves in the winter, whereas coniferous trees are marked by needles, or similarly thick and waxy type leaves that stay green through all seasons.
Despite both types of trees able to utilize what little waters they have stored in sapwoods and through soil moisture uptake to survive freezing temperatures, coniferous trees are actually more susceptible to dry winter conditions due to their leaf retention, and young trees in particular should be kept well watered following the guidelines described above for the first few years.
example of Deciduous trees
example of Coniferous trees
Keep your young conifers in particular well watered through the winter, and check soils for moisture for all trees in arid, mild climates; allowing for a slow, deep watering about once a month.
Ready For Winter?
Just because your trees have gone dormant doesn’t mean they don’t need as much care through the non-growing season. Keeping your trees watered through the winter, starting with one deep watering following soon after the first frost, will help ensure the survival of your trees.
Young trees in particular need the most attention to make sure roots get what waters they need to keep growing and keeping the upper branches alive through the coldest of the seasons.
As always, if you have any questions or comments please leave your information below, and share if you found the article helpful!
- Newly planted and young trees up to three years old need to to have moist soils at a depth of four to eight inches year round.
- Fruit trees depend on water for proper bud set come spring
- Ornamentals and non-native species need extra care in order to adapt to their new environment
- Both deciduous and coniferous may go dormant in winter, but conifers still utilize their needles and are more susceptible to drought conditions in the winter.
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