Ultra-Salt-Tolerant Paspalum

What Makes It Different

Pick this when the water is the problem, not the soil.

Every seashore paspalum is exceptionally salt-tolerant; that’s the species. SeaIsle Supreme was selected specifically to push that further, and it is the best-documented salt performer in the species — rated above SeaIsle 1 and SeaIsle 2000. Its breeder describes it as thriving on salt water and growing well on brackish, recycled or effluent irrigation.

The mechanism is the one the type page explains, running further up the scale. Salty soil pulls water out of ordinary roots, so a lawn can wilt and die of thirst in soaking wet ground. Paspalum cells stockpile protective compounds that let them keep drinking anyway. Supreme keeps doing that at concentrations where its siblings start to slip.

One honest limit. The hard numbers we have are species-level, not cultivar-level: paspalum holds quality on irrigation water to roughly 30–34 dS/m, selected cultivars survive soil salinity near 54 dS/m at modest injury, and it handles ocean-strength water around 35 parts per thousand. Supreme’s advantage over its siblings is documented as a comparison, not as its own published number. Treat it as the best-evidenced choice at the top of that range, not as a separate specification.

Who It’s For

The specific yard is defined by a water test, not a view. You belong here if you irrigate from a brackish well, run reclaimed or effluent water through a purple-pipe line, or sit on a lot that takes salt spray and occasional storm-surge flooding — or if your soil test already reads high in salts or sodium.

If you simply live near the coast but water from a normal tap, buy Standard Landscape Paspalum instead. It costs less, it’s far easier to actually get, and it already carries more salt tolerance than a lawn on fresh water will ever need.

The Cultivars

There is realistically one, which is why this page is narrow.

Why there is only one. Salt tolerance in paspalum is mostly a species trait, so breeders have had little reason to build a second cultivar around it. The germplasm work that found even higher salt tolerance (accessions like HI 101 and HI 36) has not reached retail. Supreme is what exists.

Note that Supreme is a semi-dwarf, denser than the standard landscape types. It still belongs on a rotary mower at 1.0–2.0 inches — the reel-mower grasses are on the Fine Greens-Type Paspalum page.

What Changes In Care

This is where this page really differs, and the first rule is the one people get wrong.

Water it with fresh water while it establishes. Salty, brackish or recycled water stresses young tissue and stalls root growth, even in this cultivar. The whole reason you bought it does not apply until the lawn is knitted in. Plan on a fresh-water source for the first several weeks.

After that, flushing is mandatory, not optional. Every time the lawn uses water and the sun evaporates the rest, salt stays behind and concentrates in the root zone until even this grass can’t drink. Flush with about 1 inch of fresh water at a time; a cumulative 6 inches moves 50–70% of the sodium below the roots in sandy soil. On clay it’s harder — sodium makes clay swell shut and stop draining, so those soils need gypsum at about 50 lb per 1,000 sq ft monthly, applied after core aeration and followed by a foot of leaching water. Skipping this is how a salt-tolerant lawn still dies of salt.

Two smaller adjustments. If you irrigate with recycled water, use an acidifying nitrogen source to slow the pH climb that bicarbonates cause. And watch for iron chlorosis — uniform yellowing of new leaves on high-pH ground — which foliar iron fixes quickly.

One benefit you actually collect. Because this grass tolerates salt that kills weeds, salt itself works as a selective weed treatment: research recorded 90–100% crabgrass control with almost no injury to paspalum, while bermudagrass took heavy damage. Never during establishment, though — it will kill the young grass along with the weeds.

Before You Buy

• Test your water first. This is a purchase that should be driven by a number. Get electrical conductivity and sodium levels on your irrigation source. If it comes back ordinary, buy the standard landscape page and save yourself the sourcing headache.
• Certified stock from a licensed grower only. It’s patented and can only be sold as certified sod or sprigs. There is no legitimate cheap generic.
• Expect commercial channels. Call-for-quote pricing, minimum orders, freight. Budget time as well as money.
• The bermudagrass rule still applies. Non-certified sod is often contaminated with common bermuda, which is nearly impossible to remove selectively. Salt tolerance doesn’t protect you from that; certification does.
• Don’t read salt tolerance as shade tolerance. Tree shade tolerance here is low — similar to bermuda. A shaded salty yard is still a shade problem first.
• Clearing an old lawn first? Allow the full 14-day wait before planting, and check the active-ingredient panel — consumer “Roundup” no longer reliably means glyphosate, and replant intervals differ by active ingredient.