Article Figures & Data
Tables
- TABLE 1.
Species list of roadside trees and shrubs rated for their resistance to air-borne highway salt spray
DECIDUOUS TREES INJURY RATING* Horse-chestnut Aesculus hippocastanum L. 1 Tree of Heaven ’Ailanthus altissima (Mill.) Swing 1 Norway maple Acer platanoides L. 1 Cottonwood Populus deltoides Bartr. 1 Black locust Robinia pseudoacacia L. 1 Honey locust Gleditsia triacanthos L. 1-2 Red oak Quercus rubra L. 1-2 Sugar maple Acer saccharum Marsh 1-2 English walnut Juglans regia L. 1-2 Black walnut Juglans nigra L. 1-2 Shagbark hickory Carya ovata (Mill.) K. Koch 1-2 Choke cherry Prunus virginiana L. 1-2 White ash Fraxinus americana L. 2 White elm Ulmus americana L. 2 Black willow Salix nigra Marsh 2 Mountain ash Sorbus spp. 2 Poplar Populus spp. 2 Silver maple Acer saccharinum L. 2 Chinese elm Ulmus pumila L. 2 Red maple Acer rubrum L. 2-3 Lombardy poplar Populus nigra italica Muenchh. 2-3 Basswood ’Tilia americana L. 2-3 White birch Betula papyrifera Marsh 2-3 Gray birch Betula populifolia Marsh 2-3 Catalpa Catalpa speciosa Warder. 2-3 Pear Pyrus spp. 2-3 Quince ’Cydonia oblonga Mill. 2-3 Trembling aspen Populus tremuloides Michx. 3 Largetooth aspen Populus grandidentata Michx. 3 Crabapple Malus spp. 3 Golden willow Salix alba tristis Gaud. 3 Bur oak Quercus macrocarpa Michx. 3-4 Apple Malus spp. 3-4 Hawthorn Crataegus spp. 4 Manitoba maple Acer negundo L. 4-5 Allegheny serviceberry Amelanchier laevis Wieg. 4-5 White mulberry Morus alba L. 4-5 Beech ’Fagus grandifolia Ehrh. 5 DECIDUOUS SHRUBS INJURY RATING* Siberian pea-tree ’Caragana arborescens Lam. 1 Staghorn sumac Rhus typhina L. 1-2 Japanese lilac Syringa amurensis japonica (Maxim.) Fr. & Sav. 1-2 Common lilac Syringa vulgaris L. 1-2 Honeysuckle Lonicera spp. 1-2 European cranberry-bush Viburnum opulus L. 1-3 Russian olive Elaeagnus angustifolia L. 1-3 Mock orange Philadelphus spp. 1-3 Japanese barberry Berberis thunbergii atropurpurea Chenault. 2 Burning bush Euonymus alata (Thunb.) Sieb. 2 Forsythia Forsythia x intermedia Zab. 2-3 Privet Ligustrum spp. 2-3 Alder buckthron Rhamnus frangula L. 2-3 Speckled alder Alnus rugosa (Du Roi) Spreng. 3 Flowering quince Chaenomeles lagenaria (Loisel.) Koidz. 3–4 Bumalda spirea Spirea x bumalda Burv. 3–4 Beauty bush Kolkwitzia amabilis Graebn. 3–4 Gray dogwood Cornus racemosa Lam. 3–4 Red osier dogwood Cornus stolonifera Michx. 4–5 CONIFERS INJURY RATING Blue spruce Picea pungens Englem. 1 Jack pine Pinus divaricata (Ait.) Dumont 1-2 Mugo pine Pinus mago Turra. 1-2 Austrian pine Pinus nigra Arnold 2 Tamarack Larix laricina (Du Roi) K. Koch 2 Juniper Juniperus spp. 2-3 Norway spruce Picea abies (L.) Karst. 3 White cedar Thuja occidentalis L. 3–4 Yew Taxus spp. 4 Red pine Pinus resinosa Ait. 4–5 Scots pine Pinus sylvestris L. 4–5 White spruce Picea glauca (Moench) Voss 4–5 Hemlock Tsuga canadensis L. 4–5 White pine Pinus strobus L. 5 ↵* A rating of 1 indicates no twig dieback or needle browning of conifers and no dieback, tufting, or inhibition of flowering of deciduous trees and shrubs. Ratings of 5 represent complete branch dieback and needle browning of conifers, and complete dieback, evidence of previous tufting, and lack of flowering of deciduous trees and shrubs. Under severe conditions plants rated 5 will eventually die. Ratings of 2, 3 and 4 encompass slight, moderate and extensive gradations of the above injury symptoms.