Seattle Tree Inventory

NOTE: A portion of the street tree inventory is currently being updated. New data will be posted as it becomes available.

Since 1989, almost 15,000 street trees have been planted. Approximately 54% of the trees have been paid for by residents or volunteer organizations. The City of Seattle's General Fund, Capital Improvement Projects and Federal Grants have accounted for another 45%. The remaining number of trees have been installed by private developers. Today, approximately 130,000 trees exist along Seattle's streets. Note: most of the information in the following tables is based on data collected between 1990 and 1992.

Top Seven Genera of Street Trees - % of Total

Prunus (Flowering Cherries and Plums) - 26%
Acer (Maples) - 17%
Crataegus (Hawthornes) - 8%
Malus (Crabapples) - 5%
Tilia (Lindens) - 4%
Quercus (Oaks) - 4%
Liquidambar (Sweetgums) - 4%

Top Seven Species of Street Trees - % of Total

Prunus cerasifera (Cherry Plums) - 7.24%
Prunus serrulata (Japanese Flowering Cherry) - 7.23%
Acer rubrum (Red Maples) - 5.64%
Crataegus laevigata (English Hawthorne) - 5.52%
Acer platanoides (Norway Maples) - 3.51%
Liquidambar styraciflua (Sweetgum) - 3.89%
Malus spp. (Crabapple) - 3.88%

Size (trunk diameter) - % of Total

0 to 6 inches - 46%
6 to 12 inches - 34%
2 to 24 inches - 17%
24 to 36 inches - 02%
36+ inches - 01%

Health of Existing Trees

In 1994, Seattle Transportation conducted a health study of the city's 84,000 street trees. Each tree's health was rated from 1 (poor) to 5 (great). 59% of the trees ranked ranged from good to great. 42% of the trees ranged from poor to over half-dead. Many of the trees suffer from one or more problems, including trunk-area decay, canopy defoliation, tree topping, branch structure defects and root structure problems.

The Overall Condition of Seattle's Trees - % of Total - Actual Number

Over half dead - 3% - 2,214
1/4 to 1/2 dead - 8% - 6,927
Poor - 31% - 26,211
Good - 34% - 28,860
Great - 25% - 19,704

For more information, call the City Arborist's office at 206-684-TREE (8733).