With this extra-cold winter, even gardens in warmer parts of North America are facing road salt spray damage. This is caused by very fine droplets of salty water given off by vehicles driving along a road treated with deicing products. The faster the vehicles drive in the sector, the further the salt spray penetrates onto neighboring properties. This kind of spray does not necessarily contaminate the soil (that kind of damage mostly occurs within a foot or so of the road, where particles of rock salt are deposed and that’s a different story entirely), but instead harms plants well back from the road, sometimes up to 30 feet (9 m). Damage includes reddened, dying needles on conifers, burned or scorched leaves on broadleaf evergreens and bud death and twig dieback on deciduous trees and shrubs, followed by witches-bloom growths in the summer when the plant tries to recuperate.
To avoid such damage, plant shrubs and trees that are resistant to salt spray nearest to the road. This group includes such plants as such as rugosa rose (Rosa rugosa), tamarisk (Tamarisk spp.), and shrubby cinquefoil (Potentilla fruticosa). (See more suggestions here: pubs.ext.vt.edu/430/430-031/430-031.html.) The salt will condense on the branches of these resistant plants, thus protecting the plantings in the background.
Or simply avoid woody plants near a busy road, using deciduous perennials instead. Since these plants lose their aerial parts in the fall, leaving no living stems or leaves on which salt spray can condense, they are indifferent to this kind of damage.