Landscape Architect Articles

Turf Care06-01-05 | News

Seashore Paspalum in the Landscape

By Stacie Zinn,
international marketing director,
Environmental Turf, Inc.

Seashore Paspalum can be treated with ordinary table salt to kill weeds. A high-salt brine solution spray can also be highly effective.

If you’re working in a warm-season climate and are not yet familiar with Seashore Paspalum (SP), chances are that you will be soon. Because of its highly environmentally friendly properties, fine-bladed cultivars such as SeaDwarf?EUR??,,????<

Why Seashore Paspalum?

takes up to 50 percent less water for irrigation than Bermudagrass;
requires up to 75 percent less nitrogen for fertilization than Bermudagrass;
can be irrigated with potable, effluent, brackish, even seawater under the right conditions;
does extremely well in high-salt environments (salt can be used as a herbicide on this turf);
adapts to a wide variety of soil conditions;
fairly shade tolerant, though not as shade tolerant as Zoysiagrass, however, some SPs are more shade tolerant, in general, than Bermudagrass.

Maintenance

Although SP is not difficult to care for, maintenance practices for this turf are different than many other turfgrass varieties. Nitrogen fertilization requirements are significantly reduced. Dr. Laurie Trenholm, an associate professor and turfgrass researcher at the University of Florida in Gainesville, recommends “frequent, small doses throughout the year,” of nitrogen. She indicates three to six applications that total between 3-4 pounds of nitrogen per 1,000 sq. ft. annually. (Some home lawns can get away with as little as two pounds of nitrogen per 1,000 sq. ft. annually, while golf courses can use up to six pounds of nitrogen per 1,000 sq. ft.) A low nitrogen regimen can also help reduce the incidence of thatch in SP.

Potassium and magnesium may also be used effectively on SP. Iron may be used to “green up” the turf without adding vertical growth, which can be helpful to avoid scalping.

Trenholm recommends adjusting mowing heights for SP according to the type of mower used. SeaDwarf?EUR??,,????<

If a high-speed rotary mower is used on Seashore Paspalum, Trenholm recommends heights ranging from about 1.5 to 2-inches.

It’s reported that Seashore Paspalum’s tight knit tends to keep out weeds, and its need for nitrogen fertilization is significantly reduced. Brian Speiser, owner of Brian Speiser Irrigation Inc. in Jacksonville, Florida, has been working with a new Seashore Paspalum cultivar, Aloha?EUR??,,????<

Less is more when irrigating SP. Though the turf does need some irrigation, it is fairly drought tolerant. It is better to under water SP than over water it. Over watering predisposes the plant to diseases that are usually not a problem under drier conditions.

For home lawns, once established and in the absence of natural rainfall, irrigation can be scheduled once or twice a week so that the soil is wetted to a depth of 6-8 inches. Irrigation amounts are site specific, but again, over watering is not recommended.

SP may be irrigated with a wide range in water quality. During establishment, the better the quality water, the faster the grow-in. Once established, SP may be irrigated with potable, effluent, brackish, even seawater under some conditions.

It is believed that SP came to the Americas as bedding in the bottom of slave ships. The grass was off-loaded in salty areas, such as sand dunes, and adapted to a high saline environment.
“It’s not so much the grass that gets effected, but the soil that supports it that gets effected by the salt,” said Dr. Lee Berndt of Edison College in Fort Myers, Florida. Therefore, when irrigating with highly salty water it is beneficial to flush the soil periodically to push salts through the soil column.

One of the many benefits of SP is that its tight knit tends to keep out weeds. However, in times of stress caused by over watering or over fertilization, for example, weeds may grow in the turf.

SP affords the turfgrass manager a special opportunity to use salt as a natural weed-killer. SP may be treated with ordinary table salt to kill weeds, or a high salt brine solution, administered through a sprayer, can also be highly effective.

It is important to note that not all commercial herbicides are labeled for or are safe for SP. Below are a few examples, as provided by Trenholm, of herbicides that can be used on SP.

First-hand Experience

For about a year, Brian Speiser, owner of Brian Speiser Irrigation Inc. in Jacksonville, Florida, has been working with 2,700 sq. ft. of a new cultivar called Aloha?EUR??,,????<
“It’s been absolutely painless,” Speiser said. “I don’t want to say ‘no brainer’, because we have had a couple little issues. But it’s not been something we haven’t overcome really easily.”

Those issues included a crewmember not paying attention, calibrating a deck unevenly and scalping some of the turf. Speiser top dressed the turf and fertilized with it with a basic Bahiagrass Weed & Feed.

“Really, the fertilizer and the top dressing brought it right back,” Speiser said. “If I had burned the St. Augustine section (of the property), I’d have been replacing that turf. Just straight up, I would have been cutting that grass out and putting in new turf. With the paspalum, it did grow back and it was easy to do.̶i;

Speiser has been mowing the Aloha?EUR??,,????<
“We’ve used anything from a 48-inch deck on a John Deere Zero Turn, to a little 22-inch mower, and that has actually worked better overall than the wider decks,” Speiser said. “A narrower deck does work better. It gives you more control.”

He offered some advice for contractors or turf managers thinking about maintaining SP. “As far as the installation of it, and as far as the upkeep of it, it’s not something I would be afraid of,” he said. Still, there was somewhat of a learning curve. “Initially, I had so much misinformation from people telling me about it,” Speiser explained. “Until we actually installed it and worked with it, it was hard to get a good judgment call on what it was going to be like to maintain.”

A year later, Speiser said he is now a fan of Aloha?EUR??,,????<
Editor’s note: Turf-Seed, Inc. just announced it is targeting spring 2005 to release Sea Spray??????oe, the “industry’s first and only commercially available seeded variety of seashore paspalum.”

Herbicides for SP

Broadleaf Weed Control
Weed-B-Gon??????oe products
Grassy Weed Control:
Quinclorac – Drive?EUR??,,????< Pendimethalin products
Dithiopyr – Dimension?EUR??,,????< Prodiamine – Barricade?EUR??,,????<
Sedge Control
Halosulfuron – Manage?EUR??,,????<
Note: A more comprehensive list of safe and phytotoxic herbicides is available in Suggestions for the Care of Seashore Paspalum, a book created by Environmental Turf, the company that licenses SeaDwarf?EUR??,,????<