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.