With the highest, concentrated populations living along coastlines it is important that our landscape plants be tolerant of higher soil salinity, salt spray and drift. A major component of salt is concentrated sodium, which is damaging to plant tissue, both foliage and roots. Very high salinity levels can stunt plant growth, even killing some plants. If excessive salt accumulation can be avoided then care should be taken to do so. Highly saline soils usually occur in those areas that are exposed to constant salt spray or where a lot of de-icing products are applied, these are challenging situations for arborists, land managers and homeowners.
Saline soils occur due to build of sodium in soils, this rarely happens in regions where rainfall meets or exceeds 20 inches per year. Soils with high salinity will also be found along coastlines and barrier islands where washover occurs, along or within the immediate watershed of brackish or tidal rivers and estuaries, near sidewalks and roads where de-icers are used or where snow is stored or in the vicinity which receives vehicle-generated salt spray, in cultivated areas where high salt index fertilizers are over applied, in areas where crops or landscape plants are irrigated with water containing a high salt content and areas with high groundwater tables.
Root cells in plants have a permeable membrane that allows water, but not salt, to pass through. However, when salt levels become too high it becomes very difficult for water to be absorbed into the root tissue. High salt concentrations will eventually begin to draw water out of the roots and cause “salt burn”. Plants vary in their tolerance for salt concentrations, many landscape plants are very sensitive to salt levels. Seedling trees and shrubs and transplanted vegetation will have almost no tolerance to excessive salt. The amount and duration of salt exposure will be the determining factor for tree and shrub tolerance.
Plants suffering damage due to salt spray will be more evident and identifiable faster than those incurring damage from highly saline soils. At very high levels saline soils will affect seed germination and plant growth. Stunted growth will occur, leaves, stems, fruits and roots will all be smaller than normal.Deciduous and broad-leafed plants will display leaf necrosis, marginal burning, premature leaf drop and possible death. Some may exhibit early fall color and leaf drop. Bud sets will not open and entire branches may die. Salt damage on deciduous trees and plants will usually first be noticeable in late summer, or during long periods of heat, drought or other stressor. On coniferous trees, needles will brown beginning at the tip and progressing towards the base as salt exposure continues. Salt damage on evergreen trees, either conifers or broad-leaved, usually first becomes evident in late winter, becoming more extensive and noticeable as the growing season begins. Diagnosing salt damage is difficult as many of these signs and symptoms can be caused by other environmental factors and stressors as well. Contact your arborist for help in diagnosing possible salinity issues and visit https://www.savatree.com/ for more information.
Below is a table (gleaned with permission from the Virginia Tech Cooperative Extension website: http://www.ext.vt.edu/topics/environment-resources/index.html) of some trees and shrubs known to tolerate higher salinity soils and/or salt spray, this list is, by no means, complete. Speak with your arborist before purchasing and planting trees and shrubs, they will assist you with appropriate choices and proper site selection.
Trees with salt tolerance
| Common name | Latin name | Deciduous/ Evergreen | Type of salt tolerance | Cold hardiness/Heat tolerance |
| Hedge maple | Acer campestre | D | Salt spray | 5-8/8-4 |
| Sycamore maple | Acer pseudoplatanus | D | Salt spray | 4-7/7-1 |
| Horsechestnut | Aesculus hippocastanum | D | Salt spray | 3-8/8-1 |
| Paper birch | Betula papyrifera | D | Salt spray | 2-7/7-1 |
| Gray birch | Betula populifolia | D | Salt spray | 3-7/7-2 |
| Catalpa | Catalpa speciosa | D | Salt spray | 4-8/8-1 |
| Hackberry | Celtis laevigata | D | Salt spray | 5-9/9-3 |
| White fringetree | Chionanthus virginicus | D | Saline soils | 5-9/9-5 |
| Lavalle hawthorne | Crataegus x lavallei | D | Salt spray | 5-8/8-3 |
| Japanese cedar | Cryptomeria japonica | E | Salt spray | 6-9/9-6 |
| Common persimmon | Diospyros virginiana | D | Saline soils, salt spray | 7-9/9-7 |
| White ash | Fraxinus americana | D | Saline soils, salt spray | 6-9/9-3 |
| Green ash | Fraxinus pennsylvanica | D | Salt spray | 4-9/9-1 |
| Ginkgo | Ginkgo biloba | D | Salt spray | 5-9/9-2 |
| Honeylocust | Gleditsia triacanthos | D | Saline soils, salt spray | 3-7/7-1 |
| Kentucky coffeetree | Gymnocladus dioicus | D | Salt spray | 5-9/9-2 |
| American holly | Ilex opaca | E | Salt spray | 5-9/9-5 |
| Black walnut | Juglans nigra | D | Saline soils, salt spray | 5-9/9-5 |
| Eastern red cedar | Juniperus virginiana | E | Saline soils, salt spray | 3-9/9-1 |
| Goldenraintree | Koelreuteria paniculata | D | Saline soils, salt spray | 5-9/8-5 |
| Sweetgum | Liquidambar styraciflua | D | Salt spray | 6-9/9-1 |
| Southern magnolia | Magnolia grandiflora | E | Saline soils, salt spray | 7-9/9-3 |
| Sweetbay magnolia | Magnolia virginiana | E | Saline soils | 6-9/9-6 |
| Black gum | Nyssa sylvatica | D | Salt spray | 5-9/9-5 |
| Austrian pine | Pinus nigra | E | Salt spray | 5-8/8-4 |
| White poplar | Populus alba | D | Saline soils, salt spray | 4-9/9-1 |
| Black cherry | Prunus serotina | D | Salt spray | 3-8/8-2 |
| White oak | Quercus alba | D | Saline soils | 5-9/9-5 |
| Bur oak | Quercus macrocarpa | D | Saline soils, salt spray | 3-9/9-1 |
| Pin oak | Quercus palustris | D | Saline soils | 5-8/8-4 |
| Willow oak | Quercus phellos | D | Salt spray | 6-9/9-5 |
| English oak | Quercus robur | D | Salt spray | 4-8/8-4 |
| Red oak | Quercus rubra | D | Saline soils | 5-9/9-4 |
Shrubs and herbaceous species with salt tolerance
| Common name | Latin name | Deciduous/ Evergreen | Cold/Hardiness/ Heat tolerance |
| Red chokeberry | Aronia arbutifolia | D | 5-9/9-4 |
| Littleleaf boxwood | Buxus microphylla | E | 6-9/9-5 |
| Beautyberry | Callicarpa americana | D | 5-10/12-3 |
| False cypress | Chamaecyparis pisifera | E | 4-8/8-1 |
| Summersweet | Clethra alnifolia | D | 5-8/8-3 |
| Red osier dogwood | Cornus sericea | D | 5-8/8-3 |
| Spreading cotoneaster | Cotoneaster divaricatus | D | 6-8/8-3 |
| Rockspray cotoneaster | Cotoneaster horizontalis | D | 5-7/7-5 |
| Scotch broom | Cytisus scoparius | D | 6-8/8-6 |
| Gardenia | Gardenia jasminoides | E | 7-11/12-1 |
| Rose-of-Sharon | Hibiscus syriacus | D | 5-9/9-1 |
| House hydrangea | Hydrangea macrophylla | D | 6-9/9-3 |
| St. John’s wort | Hypericum calycinum | D | 5-9/9-4 |
| Chinese holly | Ilex cornuta | E | 7-9/9-7 |
| Japanese holly | Ilex crenata | E | 5-7/7-5 |
| Inkberry | Ilex glabra | E | 5-9/9-5 |
| Anise | Illicium floridanum | E | 7-9/9-7 |
| Chinese juniper | Juniperus chinensis | E | 3-7/7-1 |
| Common juniper | Juniperus communis | E | 3-9/9-1 |
| Shore juniper | Juniperus conferta | E | 5-9/9-3 |
| Creeping juniper | Juniperus horizontalis | E | 3-9/9-1 |
| Amur privet | Ligustrum amurense | D | 3-7/7-2 |
| Wax myrtle | Myrica cerifera | E | 6-9/9-6 |
| Bayberry | Myrica pennsylvanica | D | 3-6/6-1 |
| Mock orange | Philadelphus coronarius | D | 5-8/8-3 |
| Mugo pine | Pinus mugo | E | 3-7/7-1 |
| Shrubby cinquefoil | Potentilla fruticosa | D | 3-7/7-1 |
| Purple-leaf sand cherry | Prunus x cistena | D | 4-8/8-1 |
| Cherry laurel | Prunus laurocerasus | E | 6-9/9-5 |
| Beach plum | Prunus maritima | D | 3-6/6-1 |
| Pyracantha | Pyracantha coccinea | E | 6-9/9-6 |
| Indian hawthorn | Rhapiolepis indica | E | 7-11/12-7 |
| Lady Banks rose | Rosa banksiae | D | 7-9/9-3 |
| Rugosa rose | Rosa rugosa | D | 3-9/9-1 |
| Scotch rose | Rosa spinosissima | D | 3-9/9-1 |
| Elderberry | Sambucus canadensis | D | 4-9/9-1 |
| Japanese spirea | Spiraea japonica | D | 3-8/8-1 |
| Bumalda Japanese spirea | Spiraea x bumalda | D | 3-8/8-1 |
| Snowberry | Symphoricarpos albus | D | 3-7/7-1 |
| Lilac | Syringa vulgaris | D | 4-8/8-1 |
| English yew | Taxus baccata | E | 5-7/7-5 |
| Japanese yew | Taxus cuspidata | E | 4-7/7-5 |
| Highbush blueberry | Vaccinum corymbosum | D | 5-9/9-2 |
| Arrowwood | Viburnum dentatum | D | 3-8/8-1 |
| European cranberry bush viburnum | Viburnum opulus | D | 4-8/8-1 |
Make sure to consult with your arborist even prior to choosing plants from these lists, check the hardiness zone, invasive or weed status, wetland status and possible planting sites to ensure success.
Bonnie Appleton, Extension Specialist; Vickie Greene, Graduate Student, Virginia Tech; Aileen Smith, Graduate Student, Hampton Roads AREC, Virginia Tech; Susan French, Virginia Cooperative Extension, Virginia Beach; Brian Kane, Department of Forestry, Virginia Tech; Laurie Fox, Horticulture, Hampton Roads AREC; Adam Downing, Madison VCE; Traci Gilland, Portsmouth VCE; “Trees and Shrubs that Tolerate Saline Soils and Salt Spray Drift” Virginia Tech Cooperative Extension Publication 430-031
