Seattle Seasonal Tree Care: Tips for Every Season

1. Spring: Focus on Tree Health, Pest Prevention & Growth.

Spring ends the tree’s dormancy and begins its active growth. It is the key time to inspect the tree for overall health, confirm that the tree recovered successfully from winter, and implement control methods prior to when pest numbers grow exponentially.

Health Diagnosis & Assessments:

In spring, while buds open and leaves develop, spring is the best time for a certified arborist to perform a complete health assessment. Inspect for winter damage, diagnose early signs of fungal and/or bacterial diseases, which are prevalent in the PNW (such as mold or leaf spot), and assess the soil’s fertility. When you catch diseases early, you can treat them before they become embedded and irreversible.

Fertilizer & Soil Improvement:

The tree will use the stored energy to fuel new growth; therefore, spring is the perfect time to administer a deep-root fertilizer, especially if the tree has grown in a confined space in the city or was previously stressed. The slow release of nutrients enhances the tree’s ability to fight off pests and drought and improves the tree’s vigor. We also concentrate on enhancing the soil structure to improve the absorption of nutrients and water.

Pruning & Light Trimming:

While the major structural pruning occurs during the dormant season, there is light trimming that can be done in spring to remove small, broken, or crossing branches. Also, it is the time to evaluate recent structural installation of items such as cables and bracing to determine whether or not the structures were damaged during the winter storms.

2. Summer: Stresses related to Weather, Water, & Load.

Seattle’s summer weather is quite hot and dry, placing many stresses upon trees, especially non native species and trees that have just been planted. Summer tree care is focused on providing water for the tree, reducing the density of the canopy, and clearing the area surrounding the tree.

Watering & Mulching:

Even though Seattle is known for rain, there are times of dryness during the months of July and August that require the tree to receive deep structural watering. The shallow-rooted trees are at the highest risk. We recommend using deep, slow watering and a thick layer of organic mulch to maintain the moisture in the soil and reduce the temperature of the soil around the base of the tree (keeping the mulch away from the trunk).

Crown Raising/Clearance:

There is a reasonable amount of time available in summer to raise the crown slightly, prune, and cut some of the branches back to make sure there is enough clearance between the branches and the nearby buildings, sidewalks, and streets. With the full foliage, the arborist can easily identify where the branches are obstructing sight lines or encroaching into areas that could cause property damage and/or liability issues.

3. Fall: Preparing Trees for Dormancy/Reserve Building.

Fall is a very important transition time. The tree is no longer putting its energy into growing leaves; instead, the tree will be focusing on building up stores of carbohydrates for the upcoming winter. Now is the time to take preventive measures to protect the tree from winter damage.

Second Deep Root Fertilizer Application:

Early in the fall, another application of a targeted deep-root fertilizer can help the tree build up maximum carbohydrate reserves before it goes dormant. The additional energy stored will support root development over the course of the winter and give the tree the fuel it needs for the rapid spring growth, resulting in a healthier tree.

Leaves & Leaf Spot Disease Prevention:

It is extremely important to rake up leaves, especially on trees that are prone to disease (maple and fruit trees). Decaying leaf litter is the breeding ground for fungal spores and diseases that will infect the tree again next spring. By removing the decaying litter, you break the disease cycle – one of the easiest and most beneficial steps to take in caring for your trees.

4. Winter: Structural Pruning/Hazard Reduction.

During the dormant season, winter is the time for the most structural and safety-related work. Without leaves, the arborist has a completely unobstructed view of the tree’s branch structure, allowing for precise and complex cuts.

Structural Pruning During the Dorman Season:

All major crown reductions, thinnings, and corrective pruning should take place during the winter. This timing puts less stress on the tree, reduces sap flow, and increases the rate of wound closure once spring arrives. Reducing the number of large, dead-weight branches in the winter greatly decreases the likelihood of failure due to wind and snow loads during the later part of the winter storms.

Hazard Tree Evaluation Before Winter Storms:

Before the first winter storms, a full hazard tree evaluation should be completed. The arborist evaluates for frost cracks, damage from previous years, and root heaving as a result of saturated soils. Once the arborist identifies and addresses these structural deficiencies, either by removal or cabling, the year-long tree care plan is complete.

Benefits of Seasonal Expertise for Tree Maintenance:

Tree care in Seattle is a never-ending cycle of observation, treatment, and prevention of hazards. Using the expertise of each season guarantees that each tree on your property is both safe and thriving throughout the entire year. Our certified arborists create customized, scientifically based plans for each season of the year, taking the focus away from simply cutting the tree and delivering comprehensive tree care services. For the expert advice and consistent maintenance to ensure your urban trees thrive despite the conditions of the Pacific Northwest, contact us at Seattle Tree Trim and Removal. We look forward to assisting you with the responsible management of your valuable urban canopy.