Large Deciduous Trees by J.E. Klett and C. Wilson1 Quick Facts... Trees provide shade, beauty and protection from harsh winter. Trees help moderate temperature extremes and offset poor air quality. Plant trees on the basis of space available, soil conditions, proximity to irrigation lines and water requirements. Plant trees prone to storm breakage away from buildings, walks, driveways and utility lines. Everyone enjoys the beauty a shade tree provides. Trees also reduce harsh winds, moderate temperature extremes, and offset poor air quality. How to Select a Tree To select a tree, consider the following factors. Available space. The location you choose for each tree should have enough space to allow for growth without severe pruning. Check for obstructions of buildings, overhead utility lines and tall fences. If lateral space is limited, select a tree that has a narrow, upright growth habit. Refer to height, branch spread and shape in the tree list shown in Table 1. If overhead lines are near, you may want to choose small trees. (See fact sheet 7.418, Small Deciduous Trees.) Soil conditions. Most trees perform best in well-drained soil. If you have compacted soil that is hard to work, loosen the soil and mix in organic material to a depth of at least 12 inches before planting your tree. Irrigation lines. If you have an underground irrigation system, plant trees to allow for the tree trunk and basal root flare to expand without encroaching on an irrigation pipe. Otherwise, tree roots may eventually compress the pipe and shut off the irrigation line. Growth rates vs. brittleness. As a general rule, fast-growing trees tend to be brittle and can be damaged by limb breakage in storms. Plant these trees away from buildings, sidewalks, driveways and utility lines. Water requirements. Trees vary in water requirements. Do not plant trees that have low water needs in heavily irrigated lawn areas or at the bottom of slopes. Plant trees with high water requirements in locations where supplemental watering is possible and desired. For details on watering after planting, see 7.226, Care of Young Transplanted Trees. Large Trees for Shade Table 1 includes trees that will exceed 30 feet in height when fully grown. These trees should not be placed under or near power lines or other overhead structures. Use one-half of branch spread (diameter) indicated below to determine distance from structures. Description of Tree Shapes The following tree shapes describe the general outline of the trees in the accompanying tree list. Use this chart in combination with height and branch spread to determine proper location of trees and ensure adequate clearance from obstacles. Columnar. Sides more or less parallel, much more tall than broad. Conical. Cone-shaped. Broad at base, tapering to a narrow top. Elliptical. More tall than broad, widest branching at or near the middle. Round or globe. About as broad as tall. Broad spreading. A wide vase shape. Upright spreading. A narrow vase shape. Weeping. Branches tend to weep downward.     Table 1: Large deciduous trees for shade. Plant Name Mature Size (H x W) Tree Shape Growth Rate1 Soil Moisture2 Aesthetic Value and Cultural Hints Acer plantanoides Norway maple 'Columnar' 'Deborah' 'Emerald Queen' 'Jade Glen' 'Royal Red' 'Schwendler' 50 x 40 50 x 20 50 x 40 50 x 40 50 x 40 40 x 30 50 x 40 rounded narrow, columnar rounded rounded rounded rounded rounded m m-f m m m m m M M M M M M M Dark green, dense foliage. Yellow fall color. Good for tight, narrow locations. Street tree. Red foliage changes to green in summer. Straight leader. Dark green foliage with dense branching habit. Good yellow fall color. Dark, glossy red foliage all summer. Similar to Crimson King but more cold hardy. Red foliage in spring changing to bronze and dark green in summer. Street tree. Acer rubrum Red maple 'Armstrong' 'Red Sunset' 45 x 40 50 x 30 45 x 40 conical narrow, columnar broad, conical f m f H H H Red flowers in early spring. Red fall color. Avoid very alkaline soils. Red fall color. Street tree. Avoid very alkaline soils. Red flowers in early spring. Red fall color. Avoid very alkaline soils. Acer saccharinum Silver maple 'Cutleaf' 65 x 50 50 x 40 variable rounded f f H H Bright green foliage with silvery undersides. Tends to be brittle. Yellow fall color. Avoid very alkaline soils. Deeply cut, feathery leaves. Branches tend to weep in graceful arch. Yellow fall color. Avoid very alkaline soils. Aesculus glabra Ohio buckeye 35 x 20 broad, columnar m M Reddish-orange fall color. Light yellow flowers in terminal clusters in late spring. Nut-like fruit. Aesculus hippocastanum Horsechestnut 60 x 45 broad, conical s M Large clusters of white flowers in late spring. Best used in large open lawn areas. Betula papyrifera Paper birch 40 x 25 elliptical m H Yellow fall color. Peeling bark. Betula pendula 'Gracilis' Cutleaf weeping birch 50 x 30 weeping m H Yellow fall color. Plant where soil stays cool and moist. Avoid south and west exposures. White bark. Carpinus betulus 'Fastigiata' Columnar hornbeam 35 x 15 narrow, columnar s H Dark green, glossy foliage much like elm. Plant where soil stays cool. Avoid south or west exposures. Catalpa speciosa Northern catalpa 50 x 25 narrow, columnar s M Showy, white, orchid-like flowers in early summer. Bean-like pods often remain on trees all winter. Celtis occidentalis Common hackberry 65 x 50 broad, spreading s-m L Adapts to most soils. Yellow fall color. Corky bark. Street tree. Fraxinus americana American Ash 'Autumn Purple' 60 x 50 50 x 50 elliptical round m m M M Yellow to purple fall color. Street tree. Reddish purple fall color. Seedless. Fraxinus pennsylvanica Green ash 'Marshalls' Seedless' 'Patmore' 'Summit' 50 x 30 50 x 30 50 x 30 50 x 20 round elliptical elliptical conical m m m m M M M M Yellow fall color. Adapts to wide range of soils. Yellow fall color. Street tree. Seedless. One of the hardiest. Seedless. Female will produce seed. Yellow fall color. Gleditsia triacanthos inermis Thornless honeylocust 'Imperial' 'Shademaster' 'Skyline' 'Sunburst' 65 x 40 40 x 40 70 x 50 45 x 40 35 x 45 variable rounded broad, spreading broad, conical variable m m m m m M M M M M Seedling selection. Not always thornless. Foliage is fern-like and bright green. Thornless. May produce pods. Dark green, ferny foliage. Podless and thornless. Street tree. Compact, dark green foliage. Yellow-tipped foliage. May be more prone to diseases. Gymnocladus dioica Kentucky Coffeetree 45 x 25 variable s L May be male or female. Female has leathery pods. Interesting winter form. Populus alba Silver (white) poplar 'Pyramidalis' Bolleana (white) poplar 75 x 60 45 x 15 broad, spreading narrow, columnar f f H H Leaves green above and silvery white below. Greenish-white bark. May sucker from roots. Good for fast screen planting. Short-lived due to diseases. Silvery, lobed, maple-like leaves. Populus angustifolia Narrowleaf cottonwood 50 x 40 columnar f H Yellow fall color. Root suckers, thus should be used where it can be allowed to spread in groves. Populus deltoides 'Siouxland' Cottonwood 'Siouxland' 75 x 40 elliptical f H Cottonless. This selection is very prone to cytospora canker. Populus nigra 'Italica' Lombardy poplar 60 x 15 narrow, columnar f H Use as temporary screen planting. Short-lived due to diseases. Populus sargentii Plains cottonwood 90 x 50 upright f H Native of the plains along rivers. Cottonless (male) selections available. Populus tremula 'Erecta' Upright European poplar 60 x 15 upright, spreading f H Use as screen planting. More disease resistant and long-lived than Lombardy. Populus x acuminata Lanceleaf cottonwood 50 x 40 elliptical f H Yellow fall color. Shiny, willow-like leaves. Quercus bicolor Swamp white oak 50 x 45 upright, spreading m-f M Adapts to clay soils and irrigated lawns. Fall color usually yellow. Street tree. Quercus macrocarpa Bur oak 60 x 50 broad, spreading s L Tolerates alkaline soils and drought. Quercus robur English oak 50 x 50 rounded m M Broad, stout, spreading branches. Glossy, dark green, thick-textured leaves. Street tree. Quercus rubra Red oak 40 x 50 broad, spreading m M Often broader than tall. Fall color usually red. Avoid very alkaline soils. Street tree. Salix matsudana 'Navajo' Navajo globe willow 35 x 35 globe f H Formal globe shape. Brilliant green foliage in spring. May suffer freeze injury in some area. Widely used on Western slope. Sophora japonica Japanese pagodatree 50 x 40 rounded m M Creamy flowers in midsummer. Bean-like pods in late fall. Street tree. Tilla americana American linden 60 x 50 broad, conical to columnar m M Heart-shaped leaves. Fragrant flowers in early summer. Tilla cordata Littleleaf linden 'Greenspire' 45 x 30 45 x 25 conical conical to oval m m M M Dense foliage. May sucker near base. Street tree. Near formal appearance. Glossy, dark green leaves. Street tree. Tilla x euchlora 'Redmond' Redmond linden 45 x 40 broad, conical m-f M Striking reddish bark/twigs. Narrow crotch branch habit may result in storm breakage. 1Growth rate: s = slow, m = moderate, f = fast 2Soil moisture: H = heavy water needs; more than normal lawn watering. M = moderate water needs; normal lawn watering. L = low-water needs; can withstand drought. 1J.E. Klett, Colorado State University Cooperative Extension landscape horticulturist and professor, horticulture and landscape architecture; and C. Wilson, Cooperative Extension horticulture agent, Denver County. 1/00.