Linear Arboretum

bird-in-tree-jurgens-park-by-greg-tudor-sm
photo: Greg Tudor

The Ainsworth Linear Arboretum is unique among U.S. arboretums. It spans more than 30 city blocks and showcases both existing approved city street trees and ones being trialed in actual street conditions to evaluate their performance and suitability. You can view more than 60 different species of street trees (representing about 30 genera and 18 families) within walking or bicycling distance of each other.

Many of the arboretum's trees were planted by Friends of Trees. Others were planted by individual residents or by the City of Portland's Urban Forestry program within Portland Parks & Recreation. Longtime Friends of Trees volunteer Jim Gersbach, a resident of the Concordia neighborhood, conceived the idea of the Linear Arboretum, which came into existence in 2005 by proclamation of the Urban Forestry Commission. Gersbach leads frequent tours of the arboretum from spring through late fall. Make requests for group tours by appointment (minimum 4 people) through Friends of Trees, or to find out when the next scheduled tour is.

The arboretum extends along NE Ainsworth Street for two miles, from NE Martin Luther King Jr. Blvd. to Fernhill Park. Below is a list of the trees and their addresses. Some trees are identified with metal plaques along the sidewalk giving common and botanic names and planting date. Others can be located using the list below. Note that some of the trees - like horsechestnuts, Norway maples, and American sweetgums - are legacy trees no longer considered suitable for street planting because of surface roots, invasiveness, or disease or pest issues.

Common NameScientific Namedate plantedPhysical Location
Silverleaf oak NEW! Quercus hypoleucoides 2014 (Nursery: Cistus) Second tree from west in the 500 block median 
Julian hackberry NEW! Celtis julianae April 2015 (Nursery: Forest Farm) Easternmost tree in the 500 block median
Green Vase zelkova Zelkova serrata 'Green Vase' May 2015 Four new street trees in front of new condos at corner of Ainsworth and NE 5th
Northern catalpa
Catalpa speciosa
Feb. 9, 2013 531 NE Ainsworth
Common hackberry Celtis occidentalis 2012 Westernmost tree in median in 600 block

Blue oak NEW!

Quercus douglasii  2014 Median across from 620 NE Ainsworth

 Willow oak

 NEW!

 Quercus phellos  2014 Median across from 636 NE Ainsworth
Horsechestnut Aesculus hippocastaneum pre-2000 649 NE Ainsworth
Magyar ginkgo Ginkgo biloba 'Magyar' 2006 Easternmost tree in median across from 649 NE Ainsworth
Paperbark maple Acer griseum Feb. 28, 1998 710 NE Ainsworth
Bamboo-leaf oak Quercus myrsinifolia 2003 710 NE Ainsworth
Bur oak Quercus macrocarpa   Median across from 741 NE Ainsworth
Turkish hazelnut Corylus colurna   Median across from 741 NE Ainsworth
Queen Elizabeth hedge maple Acer campestre 'Evelyn'   842 NE Ainsworth
Goldenrain tree Koelreuteria paniculata   842 NE Ainsworth
Chinese dogwood Cornus kousa 'Blue Shadow'   842 NE Ainsworth
Village Green zelkova Zelkova serrata 'Village Green'   876 NE Ainsworth
June Snow dogwood Cornus controversa 'June Snow'   876 NE Ainsworth
Emerald Sunshine elm Ulmus propinqua 'JFS Bieberach'  November 2011 (Nursery: Schmidt) Westernmost tree in median between 8th and 9th avenues
Chinese tupelo Nyssa sinensis  November 2011 Median between 8th and 9th avenues
Black oak Quercus velutina  April 2012 (Nursery: Schmidt) Median between 8th and 9th avenues
Magyar ginkgo
Ginkgo biloba 'Magyar'  2006 879 NE Ainsworth
Accolade elm Ulmus japonica x wilsoniana 'Morton'  2009 Median across from 923 NE Ainsworth
Bald cypress Taxodium distichum April 15, 2011 Median across from 923 NE Ainsworth
Swamp white oak Quercus bicolor April 15, 2011 Median across from 923 NE Ainsworth
Hedge maple Acer campestre   924 NE Ainsworth
Tuliptree Liriodendron tulipifera Feb. 9, 2013 931 NE Ainsworth
Paperbark maple Acer griseum Feb. 28, 1998 941 NE Ainsworth
Green Vase zelkova Zelkova serrata 'Green Vase'   Median between 10th & 11th streets (easternmost tree & fourth tree from east)
Frontier elm Ulmus 'Frontier'  2009 Median between 10th & 11th (third from east)
Black tupelo Nyssa sylvatica   Median between 10th & 11th (fifth from east)
Asian persimmon Diospyros kaki 'Fuyu'  May 29, 2008 1134 NE Ainsworth (westernmost tree)
Sycoparrotia X Sycoparrotia semidecidua March 27, 2010 (Portland Nursery) 1134 NE Ainsworth (middle tree)
American hornbeam Carpinus caroliniana   1134 NE Ainsworth (easternmost tree)
Mexican white oak Quercus polymorpha April 2009 (Nursery: Cistus) 1204 NE Ainsworth (westernmost tree)
Dynasty crapemyrtle (2) Lagerstroemia indica 'Dynasty' Feb. 28, 2009 1204 NE Ainsworth (on 12th St. side)
Pearlbloom Poliothyrsis sinensis April 2013 (Nursery: Forest Farm) Median across from 1204 NE Ainsworth (second tree from west)
Interior live oak Quercus wislizenii April 2009 (Nursery: Cistus) Median across from 1214 NE Ainsworth (third tree from west)
Edith Bogue magnolia Magnolia grandiflora 'Edith Bogue' Feb. 22, 2003 1306 NE Ainsworth
Japanese hornbeam (2) Carpinus japonica Feb. 28, 2009 1314 NE Ainsworth
Oregon white oak Quercus garryana   1329 NE Ainsworth
Red Sunset maple (2) Acer 'Franksred'   1335 NE Ainsworth
Bee-bee tree, evodia NEW! Tetradium hupehensis April 2015 Median across from 1325 NE Ainsworth
Thornless male osage orange (2) Maclura pomifera 'White Shield' April 2012 (Portland Nursery) Median across from 1335 NE Ainsworth
Elizabeth magnolia Magnolia 'Elizabeth' Feb. 18, 2006 1406 NE Ainsworth (easternmost tree)
Vanessa Persian ironwood Parrotia persica 'Vanessa'

Feb. 18, 2006 1406 NE Ainsworth (westernmost tree)
Chinese fringetree (3) Chionanthus retusus Feb. 18, 2006 1406 NE Ainsworth (on 14th Street side)
Oregon white oak (2) Quercus garryana Feb. 20, 2010 1425 NE Ainsworth
Staghorn sumac Rhus typhina   1503 NE Ainsworth
Fairview Flame red maple (2) Acer rubrum 'Fairview Flame'   1506-1524 NE Ainsworth
Amur maackia NEW! Maackia amurensis March 2015 1514 NE Ainsworth
Fragrant snowbell Styrax obassia Feb. 28, 2009 1524 NE Ainsworth
Autumn Gold ginkgo NEW! Ginkgo biloba 'Autumn Gold' March 2015 1525 NE Ainsworth
Southern magnolia Magnolia grandiflora   5954 NE 16th (tree on Ainsworth)
Eastern redbud Cercis canadensis Feb. 28, 1998 1715 NE Ainsworth
Katsura (2) Cercidiphyllum japonicum   1735 NE Ainsworth
Ginkgo Ginkgo biloba   June 2015 Median across from 1735 NE Ainsworth (easternmost tree)
Green Vase zelkova
Zelkova serrata
'Green Vase'
  Median across from 1735 NE Ainsworth (third tree from east)
Kentucky coffee tree Gymnocladus dioicus   5953 NE 18th Ave.
Snow gum* Eucalyptus pauciflora ssp. niphophila   1804 NE Ainsworth (in front yard)
Saucer magnolia Magnolia x soulangiana   1814 NE Ainsworth
Korean mountain ash Sorbus alnifolia   5949 NE 19th St. (tree on Ainsworth)
Edith Bogue magnolia Magnolia grandiflora 'Edith Bogue' March 27, 2010 1837 NE Ainsworth
Magyar ginkgo Ginkgo biloba 'Magyar'  February 2007 Median across from 1905 NE Ainsworth
Tuliptree (2) Liriodendron tulipifera   1929 NE Ainsworth
Tasmanian pencil pine NEW! Athrotaxis x latifolia  April 2015 (Nursery: Forest Farm) Median across from 1939 NE Ainsworth
 Umbrella pine  Sciadopitys verticillata 'Wintergreen'  March 31, 2014 Median across from 2005 NE Ainsworth
Flowering ash Fraxinus ornus Dec. 28, 2010 Alberta Park
Chinese fringetree Chionanthus retusus Dec. 28, 2010 Alberta Park
Redbud Cercis canadensis Dec. 28, 2010 Alberta Park
Sourwood Oxydendron arboreum Dec. 28, 2010 Alberta Park
Oregon white oak Quercus garryana 2009 Easternmost tree in 2100 block median 
Male Kentucky coffee tree Gymnocladus dioicus 'Espresso' April 15, 2011 (Nursery: Schmidt) Median across from 2207 NE Ainsworth
Sweetgum tree Liquidambar styraciflua  Pre-2000 2207 NE Ainsworth
Forest Pansy redbud Cercis canadensis 'Forest Pansy' March 23, 2013 (Nursery: Rigert) 2306 NE Ainsworth
Coast redwood* Sequoia sempervirens  Pre-2000 2306 NE Ainsworth (in side yard)
Queen Elizabeth hedge maple Acer campestre 'Evelyn' March 4, 2000 2316 NE Ainsworth
Mountain silverbell Halesia monticola Nov. 20, 2004 2337 NE Ainsworth (on NE 24th Street side)
Atlas cedar* Cedrus libani ssp. atlantica  Pre-2000 2406 NE Ainsworth (inyard)
Sassafras NEW! Sassafras albidum April 2014 Westernmost tree in 2400 block median
Magyar ginkgo Ginkgo biloba 'Magyar'  2006 Median across from 2407 NE Ainsworth
Chinese dogwood Cornus kousa Nov. 20, 2004 2417 NE Ainsworth
Persian ironwood Parrotia persica  Feb. 17, 2007 2426 NE Ainsworth
Persian ironwood (2) Parrotia persica  Nov. 20, 2004 2516 NE Ainsworth
Purple catalpa Catalpa x erubescens 'Purpurea'

Feb. 11, 2006

(Nursery: Dennis Seven Dees)

2519 NE Ainsworth
Chinese dogwood Cornus kousa   2529 NE Ainsworth
Forest Pansy redbud Cercis canadensis March 23, 2013 2606 NE Ainsworth
      2617 NE Ainsworth
Edith Bogue magnolia Magnolia grandiflora 'Edith Bogue'
 Pre-2000 2711 NE Ainsworth
Northern catalpa (3) Catalpa speciosa March 27, 2011 2737 NE Ainsworth
Chinese wingnut Pterocarya hupehensis June 1, 2012 (Nursery: Forest Farm) Median across from 2807 NE Ainsworth (westernmost tree)
      Median across from 2817 NE Ainsworth
American sweetgum (2) Liquidambar styraciflua  Pre-2000 2815 NE Ainsworth
American sweetgum (4)
Liquidambar styraciflua  Pre-2000 2835 NE Ainsworth
Oregon white oak* Quercus garryana   2835 NE Ainsworth
Hackberry Celtis occidentalis   Median across from 2835 NE Ainsworth
American smoketree Cotinus obovatus Feb. 17, 2007 2908 NE Ainsworth (westernmost tree)
Helmsley snowbell Styrax hemsleyanus Feb. 17, 2007 (Portland Nursery) 2908 NE Ainsworth
Chinese pistache Pistacia chinensis April 2011 2908 NE Ainsworth (easternmost tree)
Looseflower hornbeam Carpinus laxiflora

Feb. 23, 2008 (Hoyt Arboretum-donated sapling grown from seed collected in the wild in China)

2909 NE Ainsworth (on NE 29th)
Winged hackberry Pteroceltis tatarinowii Feb. 23, 2008 (Nursery: Forest Farm) 2909 NE Ainsworth (on NE 29th)
Chinese tassel tree Euptelea polyandra March 20, 2010 (Nursery: Forest Farm) 2909 NE Ainsworth (on NE 29th)
Arapaho crape myrtle Lagerstroemia 'Arapaho'  Feb. 23, 2008 2909 NE Ainsworth (on NE 29th)
Dawn redwood Metasequoia glyptostroboides Feb. 23, 2008 2941 NE Ainsworth (westernmost tree)
Shingle oak Quercus imbricaria Feb. 23, 2008 2941 NE Ainsworth
Scarlet oak Quercus coccinea Feb. 23, 2008 2941 NE Ainsworth
Sawtooth oak Quercus acutissima Feb. 23, 2008 2941 NE Ainsworth
Bald cypress Taxodium distichum Feb. 23, 2008 2941 NE Ainsworth
Katsura (4) Cercidiphyllum japonicum   2941 NE Ainsworth
Village Green zelkova (2)

Zelkova serrata 'Village Green'

Feb. 28, 2009 5941 NE 30th (on Ainsworth side) - easternmost and middle tree
American yellowwood Cladrastis kentukea Feb. 28, 2009 5941 NE 30th (on Ainsworth side) - westernmost tree
Chinese dogwood Cornus kousa   3024 NE Ainsworth
Scarlet oak (2) Quercus coccinea Nov. 20, 2004 3027 NE Ainsworth
Yellow Fever magnolia Magnolia x acuminata 'Yellow Fever' Nov. 20, 2004 3036 NE Ainsworth
Autumn Gold ginkgo Ginkgo biloba 'Autumn Gold' Nov. 20, 2004 3036 NE Ainsworth (on NE 31st) - northternmost tree
Frontier elm Ulmus 'Frontier' Nov. 20, 2004 3036 NE Ainsworth (on NE 31st)
Sterling silver linden Tilia tomentosa 'Sterling' Nov. 20, 2004 3041 NE Ainsworth
Black tupelo (2) Nyssa sylvatica Nov. 20, 2004 3041 NE Ainsworth (on NE 31st)
Henry hornbeam Carpinus henryana March 31, 2012 (Nursery: Forest Farm) Median across from 3106 NE Ainsworth
American hornbeam (2) Carpinus caroliniana Nov. 20, 2004 3116 NE Ainsworth
Chilean beech/Roble (2) Nothofagus obliqua

Jan. 23, 2009 - third tree from east (Nursery: Cistus)

Feb. 14, 2009 - easternmost tree (Nursery: Cistus)

Median between 32nd Ave. & 32nd Place
Yellow Fever magnolia (2) Magnolia x acuminata 'Yellow Fever'  Feb. 11, 2006 5955 NE 32nd St. (trees on Ainsworth)
Sweetgum tree Liquidambar styraciflua  Pre-2000 3217 NE Ainsworth
Japanese pagodatree
Sophora japonica 'Regent'  2006 Median across from 3220 NE Ainsworth
Honeylocust Gleditsia triacanthos  Pre-2000 3253 NE Ainsworth (on NE 32nd)
Green Vase zelkova Zelkova serrata 'Green Vase'  March 23, 2013 (Nursery: Rigert) 3253 NE Ainsworth
Trident maple (4) Acer buergerianum  Feb. 11, 2006 6002 NE 33rd St. (trees on 33rd)
Black tupelo Nyssa sylvatica  Feb. 11, 2006 6002 NE 33rd St. (tree on Ainsworth)
Red maple Acer rubrum
 March 27, 1999 3315 NE Ainsworth
Persian ironwood Parrotia persica  March 23, 2013 (Nursery: Rigert) 3400 NE Ainsworth
Amur maackia NEW!
Maackia amurensis  March 14, 2015  3426 NE Ainsworth (westernmost tree)
Forest Pansy redbud Cercis canadensis 'Forest Pansy'  March 23, 2013 (Nursery: Rigert) 3426 NE Ainsworth (easternmost tree)
Green Vase zelkova (3) Zelkova serrata 'Green Vase'  Feb. 17, 2007 (Nursery: Schmidt) 3436 NE Ainsworth
Dove tree Davidia involucrata  March 2006 6010 NE 35th Place (westernmost tree on NE Ainsworth

Chinese pistache Pistacia chinensis  March 2006 6010 NE 35th Place (easternmost tree on NE Ainsworth)
Natchez crapemyrtle Lagerstroemia x fauriei 'Natchez'  March 15, 2003 3576 NE Ainsworth
June Snow dogwood (2) Cornus controversa 'June Snow'  Feb. 28, 2012 3602 NE Ainsworth
Sweetgum tree Liquidambar styraciflua  Pre-2000 3624 NE Ainsworth
Tricolor European beech Fagus sylvatica 'Roseomarginata'  Pre-2000 3627 NE Ainsworth
Kentucky coffee tree Gymnocladus dioica   5953 NE Ainsworth
Japanese stewartia

Stewartia pseudocamellia

 March 23, 2013 (Nursery: Rigert)  NE Ainsworth