Exotic Tropical Garden

 

Design  •  Build  •  Plant  •  Care

 

133, Taman Stutong Indah, Lorong 12A, Jalan Setia Raja, 93350 Kuching, Sarawak, Malaysia.        

Tel: 082 363 001        Fax: 082 364 044        Hp: 019 88 88 986

 

 

QUALITY GRASS

                                                                                 

Seashore Paspalum (Paspalum vaginatum) has generated quite some interest in the turf world in the last few years.  Paspalum can now be found on a select number of Florida golf courses and has recently become available for home lawn use as well.

 

Fertilization

From work done at the University of Georgia, we know that paspalum responds best to frequent, light fertilizer applications, exactly what you don’t find happening in most home lawn fertility programs.  It grows very rapidly in response to nitrogen, again, not what you necessarily want in a home lawn.  We began two studies in Gainesville in the spring of 2000 to look at effects of common home lawn fertilizers and specific sources of nitrogen on seashore paspalum.  Over a two-year period, there were no differences in quality, shoot and root growth, or multispectral reflectance (a measurement of the plant’s ability to assimilate and use light for photosynthesis) in these studies.  Dr. Unruh found similar results in a large scale experiment looking at different sources of fertilizers in Jay.  Fertilizer source is not important in maintaining a seashore paspalum lawn.

 

Additional paspalum research was begun last year to look at effects of nitrogen and potassium rates.  Nitrogen was applied in 4 applications for a total annual rate of 1, 4, or 8 pounds of N 1000 ft-2.  Potassium was applied at the same time at annual rates of 1, 2 4, or 8 pounds of K 1000 ft-2.  as might be expected, there were differences in quality, growth, and multispectral reflectance in response to the varying nitrogen rates.  The same quality scores were achieved with either 4 or 8 pounds of N 1000 ft-2.  In reality, these rates are probably excessive for paspalum with a second year of date indicating that less N may be better.

 

Mowing Height and Frequency

Seashore paspalum generally requires lower mowing than most home lawn species.  When mowed at higher heights, it tends to shade itself out and develop excessive thatch.  However, paspalum does not like to be scalped and will decline in response to losing too much leaf tissue at one mowing.  This can be a tricky component of the management regime when combined with the rapid growth response to nitrogen and homeowner-based mowing schedules.  We began a study last year with weekly mowing heights of either 1, 2, or 3 inches.  Throughout the growing season, highest average quality scores were obtained with the higher mowing heights, in contrast to what we know is best for the grass.  Why did this happen? We lowered the mowing height too quickly when the study began and scalped the 1” treatments.  The grass never fully recovered all year and parts of it always remained scalped.

 

Establishment

Seashore paspalum has to be established vegetatively by sod, plugs, or sprigs.  While some homeowners may choose to sod, many people are purchasing plugs and letting the lawn fill in.  We began a study last summer to evaluate best nitrogen rates for grow-in.  Plugs were established in mid-July 2001 at 12 inches on center.  Two nitrogen sources and three nitrogen rates were evaluated for rate of grow-in and overall quality.

 

Fertilizer was applied in three separate applications at one week after planting, 4 weeks after planting, and 6 weeks after planting.  Nitrogen was supplied as either ammonium sulfate or sodium nitrate.  Rates were 0.25 lbs of N 1000 ft-2, 0.50 lbs of N 1000 ft-2, or 1.0 lbs of N 1000 ft-2 at each application.  There was also a control that received no nitrogen.

 

At 4 weeks after planting (one fertilizer application) and 5 weeks after planting (two applications), there were no differences in cover between that 1 lb. rate of either nitrogen source and the 0.50 lb. rate of ammonium sulfate.  During early grow-in periods with plugs, when parts of the ground are bare, the possibility of nitrogen leaching is greater.  Use of 0.50 lb. of nitrogen 1000 ft-2 will provide establishment as quickly as use of 1 lb. and will be less likely to cause leaching.

 

The Bottom Line

So, will seashore paspalum be viable as an alternative turf grass for home lawn use? Homeowners enjoy the look and feel of the grass and many are eager to try it.  However, if it is to be used in home lawns, we clearly need homeowners and lawn maintenance people who have an understanding of how to manage it properly. 

 

Irrigation

Due to the tolerance of seashore paspalum to periods of drought, irrigation is recommended on an as needed basis. Because seashore paspalum is very tolerant of poor water quality, it can be irrigated with recycled water.

 

Seashore Paspalum – A New Option for Australia

Seashore paspalum growing on a golf course in Hawaii.  This species is very well suited to the environmental and climatic conditions of tropical or sub-tropical areas. 

 

The grass species Paspalum vaginatum, or ‘seashore paspalum’ has been in existence for thousands of years, but interest in use of this grass for landscapes, athletic fields, or golf courses has occurred only in the last few years.  This is a warm-season grass that is native to tropical and sub-tropical regions world-wide.  Seashore paspalum grows naturally in coastal environments, often found in brackish marsh water or in close proximity to ocean waters.  It also grows in areas that receive extended periods of heavy rains and low light intensity.  Its best growth occurs in response to warm temperatures and long day lengths.

 

Advantages:

Seashore paspalum produces a high quality turf grass with minimal fertility requirements.  While it will exhibit best growth and quality under optimal environmental conditions, it can exist under less than optimal conditions for extended periods of time.  Some of the stresses for which it exhibits a wide range of tolerance include:

 

Seashore paspalum can grow directly on ocean beaches or nearby in a salt affected marsh:

• Excellent tolerance to saline or recycled water (to ocean salt water levels)
• Good drought tolerance under proper management
• Produces a high quality turf grass with reduced nitrogen requirements
• Tolerates a wide range of soil pHs (from 4-9)
• Minimal pesticide requirements
• Excellent wear tolerance
• Tolerates extended periods of low light intensity, such as from prolonged cloudy or rainy periods
• Good insect and disease resistance
• Tolerance to flooding or extended wet periods

 

Characteristics of paspalum that make it favorable for lawn or landscape use:

• Minimal seed head production
• Prostrate growth habit reduces mowing needs and provides for dense, fast growing cover
• Minimal weed problems under proper management
• Exhibits fine leaf texture similar to hybrid Bermuda grass
• Produces a dense root system in sand or clay soil
• Goes off-color and into winter dormancy later than other warm-season grasses

 

Disadvantage:

·        Does not perform well under tree shade

 

Fertility

Proper fertilization of any lawn grass is an important component of the best management practices of your home lawn.  Fertilization and other cultural practices influence the overall health of your lawn, and can reduce or increase its vulnerability to numerous stresses, including weeds, insects, and disease.  Seashore paspalum responds well to low fertility rates.  As with any lawn, the fertility regime will determine not only the rate of growth and curb appeal of your lawn, it will also determine the amount of maintenance required to keep it in optimal condition.

 

Mowing

Proper mowing practices are essential to maintenance of a healthy lawn.  As with fertility, height and frequency of cut can determine the level of lawn maintenance.  Seashore paspalum used in home lawns should be mowed at ¾ to 1.5 inches in height.  Higher mowing heights will reduce tigress density and increase weed problems.  Mower blades should be kept sharp to avoid tearing leaf tissue.  When mowing, never remove more than 1/3 of the leaf blade at any one time.  If the grass takes on a scalped appearance, too much leaf material is being removed at one time.  If the lawn is under stress from drought, shade, nutrient deficiencies, insects, or diseases, it is best to maintain a higher cutting height until the stress pressure is relieved.  Do not mow when the grass is wet or the soil is soggy.

 

Grass clippings can be left on the lawn.  These do not contribute to thatch build up, but are readily decomposed by microbial action.  Clippings also serve as a nutrient source, and can actually reduce the fertilizer requirements when returned to the lawn.