Dissolved/soluble salt can accumulate in soil over time from the small amount of salt that arrives from the ocean in rainfall. Salt levels or salinity can also enter your backyard via salty groundwater supplies, coastal winds depositing salt crystals on leaves, rising water tables due to land clearing and excessive use of grey water.
Symptoms of salt damage
Dissolved salts from water and soil are easily absorbed by the turf roots and transported to the leaves where they burn the leaves. High salt levels will reduce the plant’s ability to uptake nutrients and water which is result in poor growth and a poor ability to self-repair. Damage will originally be yellowing, progressing to brown and then black. The leaves may shed and the growing tips die back. The growth of young grass plants could become stunted.
Salt damaged grass may initially appear thicker, dark green and with burning signs.
Which lawns may be affected
- Varieties of turf with low salt tolerance
- Lawns installed on clay soils with inadequate drainage
- Dry soils which allow salt to accumulate
- Salt build-up is often less severe in lawns laid on sandy soils as the salt is easily leached out
What you can do
- Select a variety of lawn bred to be salt-tolerant. These turf varieties have adapted to prevent salts from entering the root systems
- Watering during hot conditions can assist in removing salts from the root system but avoid wetting the grass leaves during the day as when the water evaporates it can leave salt deposits on the leaves and cause burning. Consider installing a drip irrigation systems which maintains a moist area around to root systems and thereby forcing salts to the edge of the wet zone
- Improve the soil structure by applying gypsum to heavier clay soil as the rate of up to 5kgs per square metre. This will improve infiltration of water and assist in the leaching of the salt. You can also build-up the soil with organic matter and apply soil wetting agents on a yearly basis
- Avoid fertilisers that contain chloride or KCI (Muriate of Potash) as the potassium source
- If you use recycled grey water on your lawn consider switching to liquid washing detergents with fewer salts than washing powders
More lawn care tips and advice can be found on the Harden Park Lawns website here.