Urban Tree Replacement Program
City Light's Urban Tree Replacement Program (UTRP) mitigates for our impacts on the urban forest through outreach
and education, neighborhood tree planting projects and by replacing the trees we remove with species compatible
with our power infrastructure.
Seasonal Tree Tip - Get 'em in the Ground!
Spring is here at last, and before you know it the sun will be making a regular, daily appearance and the rain
clouds will largely be a memory. While that's great news for those of us who thrive on a little warmth and sunshine,
it means hard days ahead for newly planted trees.
From June through October the Seattle area is essentially in a drought condition. New trees aren't able to get
the water they need to help them get established and dry, hot conditions mean they loose the water in they do
have more quickly through transpiration. One of the best ways to ensure trees get off on the right foot is to
plant them when there's ample natural water and growing temperatures. That way they'll be in the best shape
they can be to combat the drought when it arrives.
The BEST time to plant in Seattle is in the fall (that's why Seattle celebrates Arbor Day in October), but the
LAST time to plant trees is somewhere around the end of April. Beyond that you're getting too close to the drought
season and the plants will need much closer attention to thrive. So what's the take away message?
If You've Got Trees Around, Get 'em in the Ground!
What Makes a "Right" Tree "Right"?
All trees are "right" in their natural environments - but what tree's natural environment is a major metropolitan
center? Cities impose many limitations on trees influencing how high they're allowed to grow (power lines, views),
how low their branches can hang (road/sidewalk clearance) and where their roots can go (sewer pipes, lifted sidewalks)
just to name a few. Unlike a natural forest the urban forest must be actively managed to avoid these kinds of
conflicts between urban infrastructure and the "wrong" trees. In the Seattle area's urban forest City Light
considers a tree to be in the wrong place when its maximum mature size will pose a recurring threat to power
delivery and public safety.
For a list of trees "right" tree species appropriate for planting under utility lines and/or along city streets
see the Seattle Dept. of Approved Street Tree List.
Our Distribution Tree Trimming Program uses directional pruning methods to train trees to grow away from our lines,
but sometimes that's not enough. When a medium/large tree grows directly underneath our lines there is little we
can do avoid a conflict. Even trees that are not directly underneath the lines but which are too close to
directionally prune must be repeatedly and aggressively cut for their entire lives. This is an inefficient and
unattractive way to maintain safety and reliable power. It also can be very bad for the tree's health. Many of
these trees, like our native Douglas fir and western red cedar, must either be topped or removed to ensure
they're kept at a safe distance. While topping and rounding were once favored as a power-line maintenance practice,
modern arboriculture (tree care) tells us that it is extremely bad for the tree.
These days when presented with the choice, City Light prefers to remove and replace a tree that's "wrong" with
one that is right and sustainable for its location. The Vegetation Management Department faces the challenge of
managing the thousands of trees that have been mistreated in the past, as well as keeping up with the new
challenges that literally grow bigger every year.
Valuing our Urban Forest and Keeping the Lights On
When a tree is in the wrong place, City Light strives to work with the responsible parties to remove that tree
free of charge, and replace it with a tree that's right for the space. While we encourage removal and replacement
in these cases, City Light will never remove a tree without first contacting the property owner, unless it poses
an imminent hazard. So what makes a right tree right?
- a tree species that won't grow too close to the lines
- a tree of any species that can be planted far enough away from the lines to avoid conflicts
The Urban Tree Replacement Program works to replace trees in one of three ways:
City Light is committed to ensuring safe and reliable power distribution and to valuing the many ecosystem
services the Seattle area's urban forest provides to everyone within our service area and beyond. Our vegetation
management professionals take pride in the work they do to keep the lines up, the lights on, and the Emerald
If you have any questions or would like more information about our Urban Tree Replacement Program
please contact City Light's Arboriculturist at 206-386-1902 or email SCLVegetation@seattle.gov
Want to Know More?
There are a number of excellent resources available to help you understand how and why to plant the right tree near
our power infrastructure - click a link below for more information: