By Natalie Carmolli, ProvenWinners® ColorChoice®
Photographs courtesy of ProvenWinners® ColorChoice®
Most landscape plants are sensitive to soil salinity, and young plants can be particularly sensitive. The amount and duration of exposure and the concentration of salt are factors to consider when diagnosing salt damage to plants.
For example, plants that are sited near roads where de-icing salts are applied may only be exposed during winter storms, while coastal areas that receive salt spray will consistently show elevated levels of soil salinity.
Because salt spray damage can look a lot like damage caused by other stressors, always consider a shrub's location when attempting to identify the cause. Consider the distance from sidewalks, roads and parking lots, or other salty water sources.
If exposed soil is deeply flushed with fresh water soon after initial exposure, salinity levels can be controlled. But of course, damage will be more severe depending on the length and amount of salt exposure.
A soil test is the best way to determine your salinity levels. Salt concentrations of 1-1000 parts per million is considered low, and 1000-2000 ppm is considered medium.
With the exception of very salt sensitive plants, most landscape plants can tolerate salt concentrations in the medium range. However, when planting shrubs in areas where they will be exposed to elevated levels of salinity, choosing more salt-tolerant shrubs is always the best bet. Here are some suggestions:
Native Aronia is known for being tough and adaptable to most any soil. Proven Winners® ColorChoice® offers three compact cultivars:
Low Scape Mound® is a dwarf selection that may be the closest thing yet to a perfect landscape plant. This versatile little black chokeberry offers dark glossy foliage, loads of white flowers in spring, black summer fruit, and intense red foliage in autumn. 24" tall/wide, USDA Zones 3-9.
Low Scape Hedger® is a narrow columnar selection that's perfect for creating hedges or mass planting. Faster to produce than 'Viking', Low Scape Hedger has white flowers in spring that appear among dark glossy green foliage which turns to vivid shades of yellow, orange, and red in autumn. 60" tall/36" wide, USDA Zones 3-9.
A new cultivar, Ground Hog™Aronia is the ideal landscape groundcover, filling in difficult spaces such as parking lot beds, slopes, or anywhere mowing would be difficult or undesirable. This dwarf Aronia naturally grows as a thick, dense mat, eliminating the need for weeding and mulching, and with the same glossy foliage, white spring flowers and dark purple berries as its counterparts. 14" tall/36" wide, USDA Zones 3-9.
Arctic Fire® (36-60" tall/wide, USDA Zones 2-7), top photo, and Arctic Sun® (48" tall/wide, USDA Zones 4-7), bottom photo, dogwood are both compact cultivars with beautiful, colorful stems. They are smaller scaled, making them an ideal choice for residential landscapes. Prized for their red and gold cut stems in holiday arrangements, their beauty belies their durability. Deer resistant, tolerant of salt and wet or dry soils, these award-winning shrubs are a great choice for four-season beauty in areas that have unique landscape challenges.
The Happy Face® series of Potentilla features large flowers that bloom from spring to late summer on a dense habit with dark green foliage. Extremely hardy, deer resistant and durable, this cheerful little plant is available in white, yellow, Pink Paradise and Happy Face® Hearts, which produces beautiful apple blossom-like flowers that are pink with a white-yellow star in the center. Varieties range from 12"-36" tall/wide, USDA Zones 2-7.
Springtime is the best time when planting trees and shrubs near roads where de-icing salts are used. This allows them to become established prior to salt exposure. Then you can sit back and enjoy the beauty of these durable, low maintenance plants.
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