How to Recover Landscaping from Salt Damage
Reversing the Effects on Plants, Lawns, Concrete, and Stonework
When your driveway and paths are covered in snow, scattering de-icing salts seems like a straightforward solution. However, de-icing salts can be problematic to your garden. Here’s how to choose the right de-icer and take a few simple precautions to protect landscaping and keep it healthy. And if you’ve already experienced damage to plants, grass, or pathways, there are ways to counteract the effects of de-icing salts.
Why is Salt so Harmful to Landscaping?
When the ice melts, the salts wash into the soil and quickly build up to a toxic level. The melted mixture leaves plants with ample moisture in the ground. But the plants are unable to absorb any of it because of all the salt. This causes symptoms of drought, including scorched leaf edges, yellow or brown needles on evergreens, stunted growth, and twig dieback. Salt buildup in the soil also has a negative effect on the soil structure because it causes compaction.
Lastly, as passing vehicles spray salty water onto trees and shrubs, the coating of salt draws moisture out of leaves and dormant buds, so that they’re unable to photosynthesize or sprout new growth in spring.
Even hard surfaces, such as concrete or stone pathways, can take a beating due to the corrosive nature of salt. On a natural stone walkway, de-icing salts can mar the surface, causing white discoloration similar to dots of bleach on a black shirt. If concrete is porous or unsealed, it can soak up the liquid brine from melted snow that’s been treated with de-icer. Then, once the absorbed water freezes again, it expands and creates pressure on the surface of the concrete, which can cause chipping, flaking, and cracks. Even the mortar that holds stone and pavers together will degrade over time if treated regularly with salt, which means bricks and pavers can loosen and become a safety hazard.
How to Choose the Right De-Icing Products for Your Landscape
De-icers and salt aren’t all created equal. Some inexpensive formulas are made of harsh chemicals that build up in the soil and cause damage to hard surfaces. Others are a little pricier, but have the benefit of being easy on vegetation and less corrosive to stone and concrete. Another consideration is how cold it will be: de-icing salts vary widely as to the temperature range in which they are useful.http://articles.chicagotribune.com/2012-01-06/news/ct-sun-garden-0108-qa-de-icing-20120106_1_calcium-magnesium-acetate-ice-melt-products-salt-laden-snow
Before applying de-icing salts, consider whether shoveling the snow and then applying some coarse sand or sawdust for traction would suffice, or whether you could mix sand with de-icer to reduce the amount of ice melting product. This not only saves money, but also gives landscaping a break. Here’s a rundown of each type of de-icer and the conditions under which each is most effective.
First Aid for Shrubs and Trees: How to Repair De-icer Damage
When you see dieback and browning or yellowing of leaves, it’s evident there’s been salt damage. If you suspect salt has leached into your landscaping, it’s wise to rinse plants and soil with water as soon as the snow melts. Apply two inches of water over a two- to three-hour period, then repeat a few days later to help disperse any residual salt. http://www.finegardening.com/preventing-and-repairing-winter-damage By reversing salt damage early, you can help your plants can leaf out.
Once the weather warms, rain helps wash off the accumulated salt on foliage, stems, and buds, and flushes salts out of the soil.
Triage for Lawns: How to Fix Salt Buildup in the Soil
Since lawns are so often next to roads, driveways, and pathways, it’s hard to avoid some amount of salt buildup in turfgrass, as evidenced by the yellowy-brown, withered leaf blades at the start of the growing season. If salty runoff has affected your grass, soak the area thoroughly over a few days’ span to rinse the salt out of the soil.
A pelletized gypsum soil conditioner can also help reverse the damage, because the calcium and sulfur in gypsum help counteract the effects of salt. This promotes new growth and helps the soil retain moisture.
To give your salt-afflicted lawn a fresh start, rake out as much of the dead grass as possible, treat with gypsum, add a thin layer of compost and grass seed, and keep the seeds evenly moist until established.
Patching up Salt Damage to Concrete, Stone, and Masonry
Salt damage to concrete and other hard surfaces can be expensive to repair. Rinse and clean the surface of the concrete thoroughly. If you see any dimples, rough spots, or shallow holes, apply a concrete patch to repair the damage, then seal it to prevent damage in future years.
If you’ve used salt on your stonework, rinse it thoroughly as soon as you can and clean the surface with a specialized detergent such as Prosoco. Then consider sealing stonework to keep it safe from future salt damage.http://www.landscapingnetwork.com/winter/ Remember: some types of salt damage and white staining may continue to worsen for a few months, so you may want to hold off until late summer to make sure you aren’t sealing stones that should be replaced instead.
Mortar can also be damaged by continued applications of salt. If any brick, pavers, or stones are loose from degraded mortar, they may need to be reset, freshly mortared, and sealed to prevent de-icers from seeping in during winter months and causing crumbling. Where safety or valuable investments including stonework or high-quality concrete are concerned, it’s always best to contact a licensed professional to complete the job.
How to Design a Resilient Landscape
Though you can choose less-corrosive de-icing products, many municipalities still use rock salt. Windy conditions and fast-moving traffic driving through slush can send sprays of salt over your landscaping and cause damage. Here are some preventative measures for designing a landscape that’s resistant to winter salt damage.
Pay attention to grading and drainage. If you direct salty runoff toward drains and away from plants or grass, you can prevent a great deal of salt damage.
Install a wall or continuous planting near the road. Consider creating a barrier between your landscaping and the salt spray off the street. A four-foot-tall wall or a thick planting of salt-tolerant shrubs running parallel to the road can block the path of salty spray across the garden. Be careful to leave enough room so snow plows or piles of snow won’t damage your wall or shrubs.
Use salt-tolerant species. Though no plants love a salty environment, some are more tolerant of it than others.http://www.gardening.cornell.edu/woodies/pdfs/saltinjury.pdf Norway maple, paper birch, white ash, European larch, Rugosa rose, Jackman’s potentilla, Vanhoutte spirea, Mugo pine, blue spruce, and common lilac are all relatively salt-tolerant.
De-icing salts are effective for keeping your landscape safe and walkable in winter. But given the price and potential downsides of using too much, it pays to explore ways of using as little ice-melting product as possible. You can enjoy the ease of de-icers without sacrificing your garden plants, lawn, or masonry if you choose the most safe and effective de-icer for your climate, then take a few reasonable precautions.