Marianne C. Ophardt
Washington State University Cooperative Extension
Area Extension Agent  

What is the ideal tree to plant for this area? It all depends on what you want in a tree. The "ideal" tree is in the "eye of the beholder."

Trees are selected for different purposes. It is important to consider the purpose a tree will fill in your landscape. A tree may meet a variety of aesthetic objectives. It may be selected for its flowering, fruiting, fall color, bark character, foliage texture or crown shape. A tree can also serve functional purposes such as screening noise abatement, traffic control, wind modification, or heat control. A shade tree is obviously selected for the shade it will provide.

Selection of a tree must involve the tree's adaptability to the location you want to plant it. It must be able to grow under the environmental conditions of wind, exposure, and soil that your selected planting site provides. You must consider the tree's ability to tolerate the extremes of temperatures in the winter and summer that it will experience in our area.

In selecting your tree you may want to consider the amount of maintenance involved with a certain tree. Leaves, fruit, nuts or seed pods are sometimes a hindrance. Certain trees will require regular pruning to keep them attractive.

Avoid trees that have severe pest problems that require regular pesticide applications to manage. Avoid trees with pest problems for which there is no control. There is usually no control for borers!

The ultimate mature size is an important factor that too few people really consider when selecting a tree. A young tree in a nursery is hard to imagine five, ten and fifteen years in the future. Trees that outgrow their space in the landscape are a nightmare. They block views. Their roots raise sidewalks and driveways and they cause concern when violent weather is predicted.

There is a tendency to select trees that grow fast and provide the most shade in the quickest amount of time. Unfortunately many fast growing species become extremely large quickly. They are prime targets for "chain saw massacres" or pruning by topping. This spoils the natural shape and beauty of the tree as well as shortening the life of the tree. Many of these speedy growers have weak wood and a disposition to develop wood rot after injuries or pruning wounds caused by topping. They also tend to be relatively short lived, not becoming the stately trees of history.

The best time to plant trees in our area is late winter-early spring after the weather moderates but before the trees open their buds and start to grow. Plants establish and grow better if planted in the spring while they are still dormant.

Fall is an alternate planting time. Evergreen trees can be planted as soon as the weather turns cooler but deciduous trees should only be planted after they drop their leaves and become dormant.

Trees planted in the spring and fall should be watered regularly, even during the winter, to keep the root zone moist. Roots are still able to grow until the soil temperature drops below 45F.

For a more extensive listing of trees, shrubs, and vines suitable for planting in Eastern Washington, refer to EB1579 "Landscape Plants for the Inland Northwest".

SYCAMORE (Platanus occidentalis) 75-100'. A very large tree which should not be planted except on the largest lots. Constantly dropping leaves, twigs, and seed clusters. Sycamore blight (anthracnose) is a serious disease problem. It appears to be very sensitive to injury from the herbicides 2,4-D and dicamba, even when used properly.

TREE OF HEAVEN (Ailanthus altissima) 40-60". This tree is adaptable to the most difficult of conditions but it is a course tree that tends to be very weedy. Should be planted only in impossible situations where nothing else survives.

SILVER MAPLE (Acer saccharinum) 50-120'. Another very large tree with a fast rate of growth. It tends to be a very weak wooded subject to many disease and insect problems. There are many superior forms of maple with many more desirable aspects. Has very little fall color. Roots are very invasive.

BOX ELDER (Acer negundo) 30-50'. This is another fast growing, weak wooded maple. It tends to be susceptible to many disease and insect problems. Very susceptible to verticillium wilt. The white variegated form has some merit. Short-lived tree.

POPLAR (Populus alba) 40-90'. This is an easy to grow "trashy" tree that continually drops leaves, twigs, and other debris. It is weak-wooded and tends to be weedy. Susceptible to many diseases and wood borers. Short-lived tree. Water seeker, invasive roots.

COTTONWOOD (Populus deltoides) 75-100'. Very large tree with all the problems of the preceding poplar. Water seeker, invasive roots.

PIN OAK (Quercus palustris) 60-70'. This is a good tree although there are many better oaks available, but it is intolerant of the alkaline soils encountered in this area.

WEEPING WILLOW (Salix sp.) 50-80'. A well loved tree but out of place in the normal home landscape. It is extremely weak wooded and very susceptible to aphids. The root system is very invasive.

RUSSIAN OLIVE (Elaeagnus angustifolia) 15-40'. Not the most beautiful of trees, but has a purpose in saline soils or where gray foliage is desired. It tends to be a rangy, weedy plant. Very susceptible to verticillium wilt, crown gall and aphids.

SIBERIAN ELM (Ulmus pumila) 50-70'. Does not deserve to be planted in the landscape. A shrubby tree with poor form. Brittle wood. Very susceptible to insects - especially aphids and the elm leaf beetle.

CRAB APPLE (Malus sp.) Crabapples are very nice trees but their fruit, large or small, are attacked by codling moth and apple maggot. Because these pests cause problems for local commercial apple growers, it’s not recommended to grow them in this region unless you intend to spray regularly with recommended pesticides to control these pests. In fact, it’s county law that you control these pests or remove your tree.

LAVELLE HAWTHORNE (Crataegus lavellei) 20-30'. A nice tree with lustrous deep green foliage and white showy flowers, but also should not be grown because it’s fruit are attacked by codling moth and apple maggot.

HEDGE MAPLE (Acer campestre) 25-35'. A nice maple for use in the home lawn. Withstands severe pruning. Tolerant of alkaline soils. The very dense crown will need thinning to permit grass to grow below.

TATARIAN MAPLE (Acer tataricum) 15-20'. A small tree for planters or street locations. Tolerant of adverse conditions. Red to red brown fall color.

EUROPEAN HORNBEAM (Carpinus betulus) 40-50'. Durable small to medium tree. Also available in smaller columnar form.

RED BUD (Cercis canadensis) 20-30'. Heart shaped leaves, early purplish-pink flowers. Tolerant of alkaline soils.

PAGODA DOGWOOD (Cornus alternafolia) 25'. White flowers in May-June. Horizontal branching habit. Very hardy. Not very available.

FLOWERING DOGWOOD (Cornus florida) 20-40'. A favorite of many people but it is difficult to establish here. It needs pampering with protection, careful watering, acidifying fertilizers, and an organic mulch. It does better in partial shade!

KOUSA DOGWOOD (Cornus kousa) 20'. Early summer flowers and bright red fruit make this shrub-like tree an interesting specimen. Fruit can be a litter problem if near walks, patios or driveways. Rich red fall color!

CORNELIAN DOGWOOD CHERRY (Cornus mas) 20-25'. Small shrubby tree. Very early yellow flowers.

GOLDENRAIN TREE (Koelreutaria paniculata) 30-40'. Attractive yellow flowers, excellent as a small lawn tree, tolerates our climate and soil conditions well.

SAUCER MAGNOLIA (Magnolia soulangiana) 20-30'. Beautiful spring flowers. Prefers acid soils.

STAR MAGNOLIA (Magnolia stellata) 15-20'. Shrub-like tree with beautiful fragrant flowers. Prefers acid soils.

FLOWERING PLUM, CHERRIES, ETC. (Prunus sp.) Many different forms of different sizes, shapes, fruiting and flowering characteristics. Many are worthwhile. Consult: Manual of Woody Landscape Plants by Michael Dirr, Sunset Western Garden Book, and The World of Trees from Ortho.

CALLERY PEAR CULTIVARS (Pryus calleryana) Variable size, according to cultivar. Good flowering and fall color.

JAPANESE PAGODA TREE (Sophora japonica) 50-75'. Lovely flowers, difficult to establish, good tree for city lots.

JAPANESE STEWARDIA (Stewardia pseudocamellia) to 30'. White camellia-like flowers in June, rich red-maroon fall color, unusually mottled bark.

RED HORSECHESTNUT (Aesculus x carnea) 30-40'. This tree is not for small yards. Its true beauty is its dark green foliage and deep red flowers. Very showy when in bloom.

RED MAPLE (Acer rubra) 50-70'. Rounded tree with good red fall color. Good for poorly drained sites.

SUGAR MAPLE (Acer saccharum) 60-120'. This is an excellent shade tree but it needs plenty of room. Orange to yellow fall color. Has some disease problems.

RIVER BIRCH (Betula nigra) 40-70'. This birch does best in moist soils and prefers an acid soil, but can be grown here if acidifying fertilizer is used. One of the most trouble-free birches and is resistant to bronze birch borer. It has an apricot colored peeling bark that is an attractive feature. ‘Heritage’ is a considered a superior selection that has good vigor and grows relatively fast.

WHITESPIRE WHITE BIRCH (Betula platyphylla japonica 'Whitespire Senior'). The only white barked birch which is bronze birch borer resistant. You must have 'Whitespire Senior' for resistance to borer.

GREEN ASH (Fraxinus pennysylvanica) 50-60'. A popular shade tree with two bad points. It has a big problem with aphids and other insects and the seeds and seedling create a nuisance. Look for 'Marshall's Seedless' cultivar for a seedless vigorous tree. Ash borers are beginning to devastate this tree and you may want to reconsider planting it.

THORNLESS COMMON HONEYLOCUST (Gleditsia triacanthos var. inermis) 30-70'. A "perfect" tree for filtered shade. A relatively new insect problem (honey locust pod gall midge) had made the tree less than "perfect." Avoid the 'Sunburst' cultivar because of this insect pest.

KENTUCKY COFFEE TREE (Gymnocladus dioicus) 60-75'. This large tree is adaptable to our harsh growing conditions. Its bark has an interesting pattern. One problem with this tough tree is the litter it creates with its seed pods and leaves. Use only in large areas.

AMERICAN SWEETGUM (Liquidambar styracifula) 60-75'. Needs room to develop roots but it is a nice tree with excellent fall color and corky bark. Prefers an acid soil and should be fertilized with an acidifying fertilizer. Few insect problems in our area. 'Moraini' is an excellent cultivar with a faster rate of growth.

AMERICAN HOP HORN BEAM (Ostrya virginiana) 25-40'. A nice, medium sized tree with many horizontal and drooping branches. Tolerates partial shade. Slow to establish.

PERSIAN PERROTIA (Parrotia persica) 20-40'. Here’s a tree with few pest problems and it has very nice shiny leaves and exfoliating bark. It’s yellow-orange-scarlet fall color is unsurpassed by any other tree. This is the perfect landscape tree. If you can find it, plant it.

RED OAK (Quercus rubra) 60-75'. An oak with relatively fast growth. Red fall color. Relatively few insect and disease problems. Interesting furrowed bark. This tree needs room, give it plenty of space to grow into.

ENGLISH OAK (Quercus robur) 40-60'. Tolerant to eastern Washington conditions. Also a narrow columnar form is available.

LITTLELEAF LINDEN (Tilia cordata) 60-70'. An excellent shade tree. Aphids may be a problem. Can be pruned into a hedge form.

SILVER LINDEN (Tilia tomentosa) 50-70'. A very nice shade tree with attractive foliage. Top of leaves are green, bottom sides are silver. Fragrant flowers in July. Tolerates heat and drought fairly well. Nice smooth gray bark. Aphids may be a problem.

CHINESE ELM (Ulmus parvifolia) to 50'. Small to medium sized tree. Relatively problem free. Interesting mottled bark. Quite drought and alkaline soil tolerant. Not to be confused with the Siberian Elm (Ulmus pumila).

JAPANESE ZELKOVA (Zelkova serrata) 50-80'. A handsome tree with an interesting growth habit. Somewhat difficult to establish. Look for the cultivars 'Village Green' and 'Halka'.