Watering Trees in Winter May Sound Unnecessary, but Don’t Overlook It – Trees Are Not Immune to Drought During Colder Months, Warns a Horticulturalist

Watering trees feels like a summer task, not something for winter. However, there are valid reasons why you should consider watering trees during winter, and ignoring the task can leave them at increased risk of harm.

Evergreen and deciduous trees can both need watering in winter. Their growth slows or stops during winter, but that doesn’t make them immune to dry conditions. If the soil is left to dry out for extended periods, trees can suffer damage to their roots and be at risk of pests and diseases.

Natural rainfall can often be enough to hydrate trees over winter, but not always, and that is something I have seen over my years as a professional horticulturist. Newly-planted trees and those in containers are at increased risk of drying out, while even established trees can suffer in dry winters. This guide reveals why you should not ignore watering trees in winter, and how to water plants efficiently.

Watering Trees in Winter: Why, When, and How

If you have deciduous or evergreen trees on your property, add monitoring their moisture levels to your winter gardening checklist.

A soil moisture meter, like this one at Amazon, offers the quickest way to check the moisture levels in the ground, letting you know when to water plants. You may not always have to water your backyard trees in winter, but they may need it for the following reasons:

Why You Should Think About Watering Trees in Winter

Deciduous trees go dormant over winter, but just because they are not actively growing, it does not mean they are unaffected by a lack of water. Even dormant plants are not immune to dry conditions; they can dehydrate and suffer damage.

Meanwhile, evergreen trees do actively grow in winter, albeit more slowly than at other times of the year. They take water from the soil at a steady rate, but lose moisture through their needles, especially to dry winter winds. Regular access to water in the soil is essential to help evergreen trees replenish the moisture they lose during winter.

A lack of water over winter can damage tree roots, reduce a tree’s overall hardiness, and leave any tree more susceptible to pests and diseases. As drying winds, the cycle of freezing and thawing, and a lack of regular rainfall impact soil moisture levels, it pays to monitor your trees.

Shallow-rooted trees, in particular, are more at risk when the top layer of soil dries, including the likes of maple, birch, willow, dogwood, hornbeam, and mountain ash trees. Newly planted specimens and trees growing in pots also require more winter watering than those in the ground.

Finally, watering trees in winter does help protect plants from frost. Moist soil acts as an insulator, absorbing and retaining warmth during the day, and releasing it at night. If you worry about low temperatures affecting trees, watering them before frosts can provide a valuable buffer against the frosts.

When to Water Trees in Winter

In many climates, natural rainfall can provide all the water required for trees throughout winter. However, it is best to check the soil levels during dry spells or periods with little rain.

Even natural rainfall may not always be enough; this can often occur with ornamental or fruit trees in pots, especially if the containers are located near walls or eaves.

Good practice is to check at least once a month, and water as required, for established ornamental trees growing in the soil. This frequency needs to increase to every few weeks for newly-planted trees and those growing in containers.

Use a soil moisture meter, and water when the top four inches of soil are dry. For watering plants in containers, use your fingers to judge, and water if the top two inches of soil feel dry.

Watering trees a few days before a frost is predicted can help shield them with a warm, insulating layer of protection ahead of the temperatures dropping.

How to Water Trees in Winter

Watering trees in winter may not be required, but when you do, there are a couple of key factors to consider. These ensure your trees are healthy throughout winter, and start growing strongly again come spring, once the warmer weather arrives.

Water trees in winter on sunny days. The soil temperatures need to be above 40°F, with no frost or snow on the ground. When conditions are right, it is also recommended to water trees in the morning, to give the moisture ample time to soak into the soil before temperatures drop later in the day.

Aim to water deeply and slowly, and attempt to soak the soil up to 12 inches down in the ground. Infrequent deep soakings are more beneficial to trees than lighter, but more frequent, bouts of watering.

Also, try to water around the dripline of the tree. This is a ring as wide as the tree’s canopy, and soaking the dripline ensures the spreading roots have access to moisture.

It is best to water wide rather than just focus on a small area around the trunk, and a soaker hose can be a useful garden tool to achieve this. A 25-foot soaker hose like this on Amazon can be used to slowly seep water deep into the soil, reducing the need for more regular watering.

Finally, mulching trees with a 2-4 inch layer of organic matter, such as compost or bark chips, will retain moisture in the soil and insulate the tree roots. Just make sure to leave 3-4 inches clear around the trunk; it is a mulching mistake to pile organic matter against the trunk, as it causes rot.

Those with drier yards can give themselves peace of mind by planting drought-tolerant trees, which can thrive even during drier periods.

The likes of a Kentucky coffeetree (you can get a live Kentucky coffeetree at Fast Growing Trees), crepe myrtle, sweet gum, and olive trees rank among some of the best drought-tolerant trees you can add to your property.

Shop Tools For Watering Trees in Winter