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 city street trees (representing about 30 genera) 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 urban forestry program within Portland Parks and 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 and American sweetgums - represent legacy plantings but are no longer considered suitable for street planting because of surface roots or disease or pest issues.

Common NameScientific Namedate plantedPhysical Location
Northern catalpa
Catalpa speciosa
Feb. 9, 2013 500 Block of NE Ainsworth
Common hackberry
Celtis occidentalis
2012 Westernmost tree in median in 600 block
Bloodgood sycamore Platanus x acerifolia 'Bloodgood' Median across from 620 NE Ainsworth
Median across from 636 NE Ainsworth
Horsechestnut Aesculus hippocastaneum 649 NE Ainsworth
Magyar ginkgo
Ginkgo biloba 'Magyar'
2006 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
Tatarian maple Acer tataricum 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 (3)
Ginkgo biloba 'Magyar' 879 NE Ainsworth
Variegated tuliptree Liriodendron tulipfera 'Aureamarginatum'  May 22, 2008 (Portland Nursery) Median across from 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
XSycoparrotia 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)
American hophornbeam Ostrya virginiana Nov. 20, 2004 1204 NE Anisworth (easternmost 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
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
Fragrant snowbell Styrax obassia Feb. 28, 2009 1524 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
Swamp white oak Quercus bicolor 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'  2006 Median across from 1905 NE Ainsworth
Tuliptree (2) Liriodendron tulipifera 1929 NE Ainsworth
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
Male Kentucky coffee tree
Gymnocladus dioicus 'Espresso' April 2012 (Nursery: Schmidt) Median across from 2207 NE Ainsworth
Sweetgum tree Liquidambar styraciflua 2207 NE Ainsworth
Forest Pansy redbud Cercis canadensis 'Forest Pansy' March 23, 2013 (Nursery: Rigert) 2306 NE Ainsworth
Coast redwood* Sequoia sempervirens 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 2406 NE Ainsworth (inyard)
Magyar ginkgo
Ginkgo biloba 'Magyar' 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
Rivers purple beech Fagus sylvatica 'Riversii' March 27, 1999 2617 NE Ainsworth
Edith Bogue magnolia Magnolia grandiflora 'Edith Bogue'
2711 NE Ainsworth
Northern catalpa
Catalpa speciosa March 27, 2011 2737 NE Ainsworth
Chinese wingnut
Pterocarya hupehensis June 2012 (Nursery: Forest Farm) Median across from 2807 NE Ainsworth (westernmost tree)
Japanese wingnut
Pterocarya rhoifolia June 2012 (Nursery: Forest Farm) Median across from 2817 NE Ainsworth
American sweetgum (2) Liquidambar styraciflua 2815 NE Ainsworth
American sweetgum (4)
Liquidambar styraciflua 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
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)
Frontier elm
Ulmus 'Frontier'