How To Prune Young Trees For Structure And Form In Seattle, WA

Structural Pruning Checklist

The purpose of structural pruning is to

• Establish and maintain and dominant leader
• Identify the lowest branch in the permanent crown and remove the ones below it (not all in one year)
• Prevent branches below the crown from growing too large
• Space main branches evenly along the dominant trunk
• Keep all branches less than ½ the thickness of the trunk by thinning and shortening them to prevent sail branches and breakage
• Suppress growth on branches with included bark (bark that grows inside that branch and puts pressure on the juncture point causing breakage)
• ALWAYS make your pruning cuts outside the branch collar (the thick part at the base of the stem), and never cut flush to the tree. 

You can download a visual guide to structural pruning here. 

Read our article on pruning fruit trees for tips on how to prune trees. 

When To Prune Young Seattle Trees

Pruning in winter: Pruning in the winter enables you to easily see the branches of your deciduous trees, identify the tree's form, and make sound decisions about what cuts to make. You can readily identify diseased, damaged, dying, and dead branches, so go ahead and prune them just above a growth point

Trees are dormant in the winter, so it’s a great time to prune your trees to encourage a burst of healthy growth in the spring. The cooler temperatures reduce the risk of exposing your young tree to diseases and insects. 

When pruning flowering or fruit trees, be careful not to cut off the buds. 

PRO TIP: Wait until after the winter solstice to avoid the pitfalls associated with fall pruning. Pruning in the fall leaves your young tree vulnerable to fungus spores, insects, and wildlife because pruning wounds are the slowest to close and heal during this time of year. 

Pruning in summer: Summer is an ideal time to remove suckers and water spouts from your young tree’s growing root stock. Summer pruning suppresses growth which is why it’s a great time to cut away those suckers and spouts. 

How Much To Prune Your Young Tree

When pruning young trees, NEVER prune more than 25% of the tree’s crown in a single year. 

Pruning more than a ¼ of your young tree’s canopy is referred to as topping or heading and spells imminent death for your tree. 

If you prune your young tree annually after its third to fifth year, there should be no need to prune more than ¼ of the crown. 

A Word Pruning Young Trees Along The Street In Seattle

If you planted your young trees in the street right-of-way in front of your Seattle home or property, there are a few things you need to know.

First, the Seattle Department of Transportation (SDOT) is responsible for maintaining SDOT-planted trees only.

The property owner's responsibility is to care for all other trees in the street right-of-way. Care includes watering in the dry season, mulching to conserve water and inhibit weed growth, and pruning to reduce conflicts with human activity and maintain the tree's health and structure.

If you plan to prune branches larger than 2" or more than 15% of the crown or canopy on a street tree, you must obtain a free tree pruning permit from SDOT. Failure to do so will result in penalties and fines. 

For more information about pruning trees in the right-of-way, contact the SDOT Arborist's Office at Seattle.Trees@seattle.gov or 206-684-TREE(8733).



Click here for a list of Seattle tree service companies with an SDOT Annual Permit to work on street trees.

Why Hire An Arborist To Prune Your Seattle Young Trees?



A certified arborist has the knowledge and experience to determine the best way to prune your young tree to ensure it thrives. They have a wealth of knowledge of the various tree species and can determine the best pruning techniques for your specific tree. A Seattle arborist is the best resource for helping you give your trees the best care possible. 

Are you concerned about diseases or pests harming your young tree?

An arborist can diagnose the problem and address it quickly. They can also identify issues or hazards with any trees or shrubs in your yard and help you make informed decisions about how best to rectify them. 

The City of Seattle requires that anyone pruning, removing, and planting trees register with the city and obtain any necessary permits before proceeding. If you choose to have a local tree service take care of your structural pruning needs, make sure they are registered with the city and have any required permits on hand to avoid penalties and fines. 

ADDITIONAL RESOURCES

https://www.seattle.gov/trees/planting-and-care/pruning#:~:text=Select%20the%20lowest%20permanent%20branches,cut%20flush%20with%20the%20tree.

https://www.seattle.gov/trees/planting-and-care/young-tree-care

https://www.yourleaf.org/blog/jess-wilkin/sep-25-2020/importance-pruning-young-trees#:~:text=Young%20trees%20should%20be%20structurally,removed%20in%20any%20one%20year.

https://www.growingagreenerworld.com/tree-topping-what-you-dont-know-is-killing-your-trees/