If you live anywhere near the Intracoastal, a canal or the beach, salt is part of lawn care whether you think about it or not. It arrives in big doses, when a king tide or storm surge pushes seawater over the seawall. It also arrives in small doses every day, from ocean spray, reclaimed water irrigation and saltwater pools.

The good news: most South Florida lawn grasses handle more salt than people expect. The bad news: once salt builds up in the root zone, there’s only one way to get it out. This guide covers what salt damage looks like, how to flush it after a flood, which grasses hold up best, and what irrigating with reclaimed water means for your lawn.

What Salt Damage Looks Like

Salt pulls water out of roots, so a salt-stressed lawn looks thirsty even when the soil is wet. UF/IFAS lists the signs: wilting, stunted growth, chlorosis (yellowing), and leaves that turn a darker, bluish-green than normal (UF/IFAS MG447). In bad cases, you may see a white crust on the soil surface.

Salt also makes potassium and magnesium harder for grass to take up, so a salty lawn can look nutrient-starved even when it’s been fed (UF/IFAS MG447).

The only way to know for sure is a test. A soil test that includes electrical conductivity (EC) measures salinity directly. When we test soil in Palm Beach County, we look for salt stress and flag irrigation patterns that make it worse.

After a King Tide or Storm Surge: How to Recover

UF/IFAS is blunt about salt in the root zone: once it’s there, the only way to get rid of it is to leach it out with fresh water (MG447). Here’s the order to work in.

1. Rinse the grass first. Wash the blades with a stream of fresh water to remove salt and any silt or debris the water left behind (UF/IFAS EP068). A layer of dried mud will smother turf even if the salt doesn’t.
2. Check your irrigation water. If your sprinklers draw from a canal, lake or well that flooded, it may be salty too. Watering with it can make things worse (EP068). Use city or utility water to flush until your source is tested.
3. Flush the soil deeply. Water heavily enough to push salt down past the roots, more than a normal watering. Rain is your friend here: a few heavy downpours do much of the work for free. Keep the soil from drying out, because drying lets salt crust on the surface (EP068).
4. Stay within watering rules. Extra irrigation may run into local watering restrictions, which UF/IFAS flags as a real limit on flushing (MG447). Check your days in our South Florida lawn watering guide.
5. Skip gypsum unless a test calls for it. Gypsum helps when sodium builds up in the soil, but UF/IFAS notes that sandy soils rarely need it after a storm (EP068). A soil test that measures sodium tells you whether it’s worth the money.
6. Hold the fertilizer. Most fertilizers are salts. Adding them to salt-stressed turf piles on the problem. Wait until the grass is actively growing again.
7. Give it a few weeks before deciding. Damage often looks worse before recovery starts. Pull gently on a few runners: firm, green ones will regrow. Areas that stay brown and lift easily after several weeks of flushing need new sod.

If a big section didn’t make it, plan to replace it with a grass that tolerates salt better, which is the next question.

Which Grasses Handle Salt Best

No lawn grass can live on seawater, but some recover from a salt event far better than others. UF/IFAS rates the common South Florida lawn grasses like this:

Sources: UF/IFAS EP068; UF/IFAS Gardening Solutions.

In practice, the bigger difference is between grasses and everything else in the yard. Many ornamental shrubs and annual beds are far more salt-sensitive than turf, so the lawn often bounces back while the hedges don’t. For waterfront yards that flood often, it’s also worth fixing grade and drainage so seawater doesn’t sit; see our guide to fixing poor drainage in Florida lawns. Choosing between St. Augustine and Zoysia for a coastal lot? Our St. Augustine vs. Zoysia comparison covers shade, wear and maintenance too.

Watering With Reclaimed Water

If your sprinkler lines are purple, you’re probably on reclaimed water: wastewater that’s been treated, filtered and disinfected for irrigation. Palm Beach County Water Utilities sends about 13 million gallons a day of it to residential lawns and golf courses, and it’s not subject to the county’s irrigation restrictions (Palm Beach County). Boca Raton runs its own system, IRIS, serving more than 1,600 homes (City of Boca Raton).

Is reclaimed water bad for grass? Generally, no. UF/IFAS says many Florida turfgrasses have moderate to high salt tolerance, so irrigating with reclaimed water shouldn’t hurt the lawn (UF/IFAS SS587). The plants that struggle are usually salt-sensitive shrubs and bedding plants, especially when sprinklers wet their leaves.

It also contains fertilizer. Reclaimed water carries traces of nitrogen and phosphorus (Palm Beach County). UF/IFAS says it can supply part of the nitrogen and all of the phosphorus a lawn needs, so counting it can let you cut back on fertilizer (SS587). The amount varies by treatment plant.

How to manage a lawn on reclaimed water:

• Don’t overwater because it’s cheap. Unrestricted water is tempting, but extra irrigation washes nutrients out and invites fungus. Water to the lawn’s needs, as in our South Florida watering schedule. Overwatering is also a common cause of St. Augustine thinning out.
• Adjust your fertilizer. Factor the nutrients in your water into your program, and remember that Palm Beach County’s fertilizer rules vary by city.
• Keep spray off sensitive plants. Aim heads at the lawn and use drip or low-angle nozzles in shrub beds.
• Test if something looks off. UF/IFAS suggests testing your irrigation water for pH, salinity and nutrients (SS587). A soil test shows whether salt is building up in the root zone.

Other Ways Salt Gets Into Your Yard

Floods get the attention, but slow, everyday salt can do just as much damage over time. UF/IFAS points to coastal spray, salty irrigation water and excessive fertilization as the usual culprits (MG447).

• Ocean spray. On the first few blocks from the beach, wind-driven spray coats leaves with salt. A fresh-water rinse after a big onshore blow helps shrubs more than the lawn.
• Too much fertilizer. Fertilizers are salts. Heavy or frequent applications on sandy soil can build up in the root zone, which is one more reason to follow label rates and a South Florida fertilizer schedule.
• Saltwater pools. Splash-out and draining a saltwater pool onto the lawn can brown the grass along the deck. Drain to an approved spot and rinse the edge strip with fresh water after heavy use. Our guide to sod around pool decks covers the strip next to the pool.
• Private wells near the coast. Wells close to tidal water can turn brackish over time. If your irrigation comes from a well and the lawn declines near the water, have the water tested.

FAQ

Will my St. Augustine come back after saltwater flooding? Often, yes, if the water drained within a day or two and you flush the soil afterward. St. Augustine has medium salt tolerance. Check the runners after a few weeks of rain or irrigation: firm, green runners mean it’s recovering.

How long should I wait before re-sodding? Until you’ve flushed the area well and either a soil test shows salts are down or several heavy rains have come through. New sod laid on salty soil struggles to root. Our guide to how long sod takes to root explains what healthy establishment looks like.

Do I need to fertilize less on reclaimed water? Possibly. It carries some nitrogen and phosphorus, and UF/IFAS says you can account for that and reduce nitrogen fertilizer. A soil test is the best way to set your program.

Can I use reclaimed water on my vegetable garden? Ask your utility. Rules on edible crops differ from lawns, and the safest assumption is to keep reclaimed water off anything you’ll eat raw.

Is gypsum a fix for salt? Not usually on our sandy soils. It’s useful only when sodium has built up, which a soil test that measures sodium will tell you.

Waterfront Lawn Taking a Beating?

We test soil for salt stress, flush and rebuild salt-damaged lawns, and install grasses suited to coastal yards across Palm Beach County. Text us a photo of the damage and where the water came from. Call or text 561-941-GROW, or see our sod installation options.

Sources

• UF/IFAS Extension, ENH149/EP068: Promoting Turf Recovery Following a Hurricane (Unruh, Lindsey, Schiavon and Trenholm, rev. Oct. 2024)
• UF/IFAS Extension, SL262/MG447: Tackling Soil Salinity Problems in the Home Landscape (Shober and Reisinger)
• UF/IFAS Extension, SS587: Maximizing the Benefits of Reclaimed Water for Irrigating the Landscape (Hochmuth et al.)
• UF/IFAS Gardening Solutions, Salt-Tolerant Lawngrasses
• Palm Beach County Water Utilities, Reclaimed Water
• City of Boca Raton, Reclaimed Water (IRIS)

Featured image: King tide flooding in a Miami Beach park. Photo: B137, CC0, via Wikimedia Commons.