Keep Your New Zealand Trees Healthy: Winter Care Tips

Winter in New Zealand, while milder than in many parts of the world, still poses specific challenges to our trees and shrubs. The drop in temperatures, potential frosts, and occasional snowfalls in certain areas can stress our green companions. However, with proper winter tree care and preparation, your trees can not only survive but thrive through the winter months, ready to burst into life come spring. Here are essential tips from an arborist to ensure the health and vitality of your trees during the New Zealand winter.

1. Understanding the Dormancy Cycle

First and foremost, it’s crucial to understand that most trees enter a dormancy phase during the winter. This natural cycle keep trees healthy and allows them to conserve energy and withstand colder temperatures. While your trees might seem inactive, winter is a critical period for their health, setting the stage for spring growth.

2. Mulching: A Winter Shield

Mulching is your tree’s best friend during the cold months. A generous layer of organic mulch around the base of your trees can act as an insulating blanket cover susceptible trees, protecting roots from extreme temperatures. It also retains moisture, which is vital as the winter winds can dry out the soil. Aim for a mulch layer of about 2-4 inches, keeping it a few inches away from the trunk to prevent rot.

3. Pruning: The Art of Preparation

Winter, with its dormant phase, is the ideal time for pruning most tree species. Removing dead, damaged, or diseased tree branches now can prevent potential hazards and promote healthier growth in spring. However, it’s essential to understand the specific pruning needs of each tree species, as incorrect pruning can lead to stress and damage.

4. Watering: Winter’s Hidden Need

While it’s easy to think that the cooler weather diminishes the need for watering, your trees still require adequate hydration, especially in early winter or if the season has been particularly dry. Watering in the early part of the day ensures that the water has time to soak into the ground before the cooler temperatures at night. This is especially important in dry soil and for young trees or those planted within the last two years.

5. Pest and Disease Management

Winter is a great time to inspect your trees for signs of pests and diseases. Early detection and treatment can prevent more severe issues in the spring. Keep an eye out for any abnormalities in the bark, leaves (on evergreens), and the surrounding soil. Employing environmentally friendly pest control methods can help with tree health and maintain the ecological balance in your garden.

6. Protecting Young Trees

Newly planted trees are particularly vulnerable to winter stresses, including frost and strong winds. Consider using tree guards or wraps to protect the bark from frost cracks and rodent damage. Staking young trees can also provide additional support against strong winds, ensuring they remain upright and secure.

7. The Right Time for Planting

Believe it or not, winter can be an excellent time to plant certain tree species in New Zealand, especially deciduous trees. Planting during the winter season of dormancy allows the newly planted tree to establish roots in its new location without the stress of supporting leaf growth, giving it a head start when spring arrives.

8. Protecting Tree Roots and Soil

The soil and roots system acts as a storage unit for the earth’s warmth, which can be crucial in protecting trees during cold temperatures. Applying a thin layer of organic matter around the base of your trees can help insulate the root system, keeping it from freezing when the ground freezes. This is especially important for newly planted trees whose root systems are not yet fully established. Maintaining a moist (but not waterlogged) soil can also help more solar radiation to be absorbed, providing additional warmth during the cold weather.

9. Covering Susceptible Trees

To protect trees from frost, snow and ice damage, as well as from animals that may eat shrubs or girdle trees (strip the bark from the tree trunk, which can also lead to tree death), consider using plastic tree guards. These winter tree guards can protect the tree trunk from animal damage and prevent cold injuries to young trees with thin bark. For susceptible trees, especially newly planted ones, wrapping or covering can shield them from the harsh winter sun and freezing temperatures that can cause bark splitting.

10. Potted Plants and Trees

For potted plants and trees, moving them to a sheltered location can help protect them from the worst of the winter’s chill. This is because potted specimens are more exposed and can benefit from being placed where they can receive more solar radiation or be shielded from the cold winds.

planting in pots

11. Professional Advice: When to Seek Help

While many aspects of winter tree care can be handled by garden enthusiasts, there are situations where it’s best to seek out certified arborists for professional advice. If you’re unsure about the health of your trees, proper pruning techniques, or specific care requirements, consulting with a certified arborist can provide peace of mind and ensure the best outcomes for your trees.

Conclusion

Winter tree care in New Zealand requires a thoughtful approach to protect trees from the challenges posed by colder temperatures, snow, and ice. From ensuring the soil and tree roots are well insulated to proper pruning techniques and protecting young, susceptible trees, every step taken can contribute significantly to the overall health of your trees this winter. By following these guidelines, you can help your trees not just survive but thrive during the winter, ready to grow vigorously as the warmer months return.

Picture of Dylan Heath

Dylan Heath

Dylan Heath is a fully qualified arborist with over 13 years of experience working in both the private and local council sectors. He comes with a wealth of knowledge, skill and passion for arboriculture.