Learn about salinity and related concepts

Learn about the effects of salt on plants

Photo: Turf and soccer player

About the difference the plant makes

Different types of plants vary considerably in their tolerances to the total amount of salt and to concentrations of sodium, chloride, and boron. For instance, turf grasses, most annuals, and deciduous plants typically tolerate more salt than evergreens do. Because they are frequently mowed, turf grasses do not normally accumulate high levels of salt. Also, they usually tolerate more sodium, chloride, and boron than other types of plants. Most annuals do not accumulate high levels of salt within their yearly life span. Many deciduous plants do not accumulate salt in their leaves, as they shed their leaves every autumn.

Photo: A salt-tolerant plant

A salt-tolerant plant

Different species of plants also vary in their tolerance to total salt and to sodium, chloride, and boron. The more tolerant species are better able to adjust osmotically and to extract more water in the presence of a moderate to high amount of total salt and moderate to high concentrations of sodium, chloride, and boron. Examples of extremely tolerant plants include Alkali Sacaton grass, the Mexican Pinon pine tree, the Norfolk Island pine tree, Oleander, and Red Apple ice plant. All of these plants can tolerate 10 decisiemens per meter or more. When irrigated with such saline water, they require no more than a routine amount of management. If possible, choose a tolerant plant in the first place or replace a less tolerant plant with a more tolerant one.

Tolerances to salt of selected turf grasses and other landscape plants
Sensitive Moderately Sensitive Moderately Tolerant Tolerant
annual bluegrass annual ryegrass blue decaena alkaligrass
colonial bentgrass coast redwood coast live oak Bermuda grass
cotoneaster cork oak European fan palm bougainvillea
crape myrtle creeping bentgrass forsythia brush cherry
ginkgo fine-leaf fescue frangipani Chinese tallow tree
Kentucky bluegrass Italian cypress oleander croceum ice plant
liquidambar Japanese boxwood perennial ryegrass evergreen pear
Oregon grape orchid sage rosemary Mexican stone pine
photinia southern magnolia tall fescue Norfolk Island pine
Pyrenees xylosma weeping bottlebrush seashore paspalum
star jasmine yellow sage zoysiagrass white/purple ice plant
Photo: Young landscape plants or shrubs

Young landscape plants or shrubs

For many plants, tolerance to salt or to sodium, chloride, or boron also varies, depending on the plant's stage of growth. Some plants are less tolerant when germinating and emerging and more tolerant when established and mature. Minimizing such a plant's exposure during the more sensitive stages of its life cycle may help to mitigate the effects of salt. Leaching salt from the intended root zone before planting is one way to do so. Another is to irrigate enough to prevent the soil from drying while the plant is becoming established. When a soil dries, salt may become concentrated closer to the plants' roots.

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