By Nancy Penrose
As temperatures begin to drop and winter approaches, it’s important to prepare your young trees for the colder months ahead. Newly planted trees are particularly vulnerable to freezing temperatures, drying winds, fluctuating soil temperatures, and winter damage. Fortunately, a little preparation in the fall can go a long way toward keeping your trees healthy.
One of the most effective ways to protect young trees is through proper mulching. Combined with a few other winter protection techniques, mulching can help ensure your trees survive the winter and emerge healthy and ready to grow in the spring.
Why Young Trees Need Extra Protection in Winter
Established trees generally have extensive root systems that help them withstand winter conditions. Young trees, however, are still developing their roots and are more susceptible to environmental stress.
During winter, young trees may face several challenges, including:
- Freezing temperatures: Extreme cold can damage roots, branches, and bark.
- Temperature fluctuations: Repeated freezing and thawing can stress roots and sometimes cause frost heaving.
- Dry winter conditions: Cold winds and frozen soil can prevent trees from absorbing enough moisture.
- Animal damage: Deer, rabbits, and rodents may feed on tender bark and branches.
- Sunscald: Sudden temperature changes on exposed trunks can damage bark, particularly on young trees.
Taking preventive measures before winter arrives can significantly reduce these risks.
The Benefits of Mulching Young Trees
Mulching is one of the simplest and most beneficial things you can do for a young tree.
A properly applied layer of mulch helps regulate soil temperatures, and keep roots insulated against sudden temperature changes. Mulch also helps retain soil moisture, reduces weed competition, and gradually improves soil quality as organic materials break down.
In the Pacific Northwest, where winters often bring substantial rainfall and occasional freezing temperatures, mulch can be especially helpful in protecting young root systems.
However, the way mulch is applied is just as important as the mulch itself.
How to Properly Mulch Young Trees
Follow these steps to give your young trees the best protection.
1. Choose the Right Mulch
Organic mulch is generally the best choice for young trees. Good options include:
- Shredded bark
- Wood chips
- Composted leaves
- Pine needles
- Arborist wood chips
These materials help insulate the soil while allowing water and air to reach the roots.
Avoid using materials that form dense, compacted layers that prevent water from penetrating the soil.
2. Apply Mulch at the Correct Depth
Spread approximately 2 to 4 inches of mulch over the soil surrounding the tree. For many young trees, a 2-to-3-inch layer is sufficient, particularly in areas with heavy or poorly drained soil.
Too little mulch may not provide adequate insulation, while excessive mulch can restrict oxygen movement and contribute to overly wet conditions.
3. Keep Mulch Away From the Trunk
One of the most common mistakes homeowners make is piling mulch directly against the tree trunk.
This practice, often called “volcano mulching,” can trap moisture against the bark, encouraging decay, disease, and insect activity.
Instead, keep mulch several inches away from the trunk, leaving the root flare exposed.
4. Extend the Mulch Ring
Ideally, mulch should extend outward toward the tree’s drip line, which is the area beneath the outermost branches.
For newly planted trees, create a generous mulch ring around the planting area. Wider mulch rings help reduce competition from grass and weeds while protecting developing roots.
Water Young Trees Before Winter
Although winter often brings abundant rainfall to the Pacific Northwest, young trees still need adequate moisture before the ground freezes.
During dry fall weather, water young trees deeply so moisture reaches the root zone. This is particularly important for newly planted evergreens, which continue losing moisture through their foliage during winter.
Avoid overwatering, especially in poorly drained soils. Saturated soil can deprive roots of oxygen and contribute to root problems.
Protect Young Tree Trunks From Winter Damage
Mulching protects roots, but young tree trunks may need additional protection.
Tree guards or protective wraps can help prevent damage from rodents, rabbits, and other animals that feed on bark during winter.
In areas where deer are common, temporary fencing may be necessary to protect young trees from browsing and rubbing.
Some young trees with thin bark, such as certain maples and fruit trees, may also benefit from appropriate trunk protection against sunscald.
Use breathable materials designed for trees, and remove temporary wraps when they are no longer needed to prevent moisture buildup or constriction.
Avoid Heavy Pruning and Late Fertilizing
Fall is generally not the time for aggressive pruning of young trees.
Remove dead, damaged, or diseased branches when appropriate, but avoid unnecessary heavy pruning before winter.
Likewise, avoid applying high-nitrogen fertilizers late in the growing season. Excessive nitrogen can encourage tender new growth that may be vulnerable to freezing temperatures.
Allow your trees to naturally transition into winter dormancy.
Give Your Young Trees a Healthy Start Next Spring
Preparing young trees for winter doesn’t require complicated equipment or expensive treatments. Proper mulching, adequate watering, trunk protection, and protection from harsh winds can make a substantial difference in their survival and long-term health.
For homeowners in the Pacific Northwest, fall is an excellent time to inspect recently planted trees and make sure they’re ready for the
colder months.
By taking a few simple precautions now, you can help young trees develop stronger root systems, reduce winter stress, and encourage healthy growth when spring arrives.
Remember: A healthy tree starts with healthy roots, and proper winter protection is one of the best investments you can make in your landscape.
Nancy Penrose is the owner of Big Trees Inc., located in Snohomish, WA in the Seattle area. The company is one of the largest tree nurseries in the Seattle area with over 120,000 trees available in over 300 varieties. They not only deliver young trees, but also mature trees in a wide range of sizes. Some types of trees available include fall color, spring flowering, deciduous, evergreen, and privacy trees.
The company also does tree transplanting, including large trees. Their blog can be seen at https://bigtreesupply.com/blog/ or http://arboristblog.com/. They can be reached at 360-563-2700.
Big Trees Inc.
10928 Springhetti Rd
Snohomish, WA 98296
360-563-2700