Bahiagrass for Florida lawns

Bahiagrass (Paspalum notatum Flugge) was introduced from Brazil in 1914. It was originally used as a pasture grass on the sandy soils of the southeastern United States. Additional varieties have been introduced since that time for use as lawn-grasses. Bahiagrass is a popular low-maintenance lawn-grass for infertile soils. Although bahiagrass does not produce a high-quality, dense, dark green lawn like some other warm-season lawn-grasses, it does provide a good low-maintenance lawn where slightly reduced visual quality is acceptable. 

Advantages

Bahiagrass forms an extensive root system, which makes it one of our most drought-tolerant grasses. It performs well in infertile, sandy soils and does not require high inputs of fertilizers. It does not form excessive thatch. It may be grown from seed, which is abundant and relatively cheap, or it may be established from sod, sprigs, or plugs. It has relatively few disease problems, and mole crickets are the only primary insect problem. 

Disadvantages

Bahiagrass forms tall, unsightly seed-heads throughout the spring, summer, and fall months. This necessitates mowing on a regular schedule. Because the seed stems are tough, it also makes it more difficult to mow than some other grass species. Bahiagrass does not perform well in high-pH soils and is susceptible to mole crickets. It does not have good tolerance to shade, traffic, or saltwater. With the exception of Pensacola bahiagrass, there is little tolerance for cold temperatures in this species. 

Leaves of bahiagrass may tend to turn yellow as a result of iron deficiency. This deficiency can be alleviated by modification of soil pH or application of iron fertilizer. For more information on iron deficiency, please refer to "Fertilization" in this publication.

Bahiagrass displays an open growth habit, which can result in encroachment of weeds into sparse areas. In addition, bahiagrass has a low tolerance for many herbicides, making chemical weed control difficult. It has a coarse leaf texture and provide less cushioning for recreational activities than some other species. 

Varieties

There are four cultivars of bahiagrass available for home lawn or utility use. These may all be established by seed or sod. 

Common

Common Bahiagrass is a coarse-textured, light-colored bahiagrass. It has an open and sparse growth habit and is very susceptible to cold temperatures. It is not normally recommended for use as a lawn-grass.

Argentine

Argentine forms a relatively dense sod and has a dark green color, making it acceptable for lawn use in many situations. It has wider leaf blades than Pensacola bahiagrass. it has good insect and disease resistance and tolerates cold temperatures well.

Pensacola

Pensacola bahiagrass was selected in Pensacola, Florida in 1935 and is the most widely grown bahiagrass today. It has an extensive root system, which imparts excellent drought tolerance. it also tolerates either hot or cold temperatures well. It produces an abundance of seed-heads, which reduces its desirability for use as a lawn-grass, but makes it suitable for roadside plantings. It has longer and narrower leaf blades than Argentine. 

Paraguay

This cultivar is also known as Texas bahiagrass. it has short, tough, hairy leaves that have a grayish tint to them. It does not have good cold tolerance and is susceptible to dollar spot disease. it does not perform as well in the lawn as Argentine or Pensacola. 

Maintenance of Bahiagrass

Establishment

Bahiagrass can be established as sod or seed. Advantages of planting a bahiagrass lawn from sod are rapid establishment of the lawn and less opportunity for weed pressure or other stresses to cause problems. The primary disadvantages of this method are the expense and the labor required to lay in the sod. In contrast, Bahiagrass seed is not expensive and seeding requires less labor than sodding. Scarified seed, which has been chemically treated to enable faster germination, should be used when available. 

Plugging or sprigging bahiagrass is not typically recommended. Because of the slow growth habit of bahiagrass, the plugging method will leave open areas of soil that can be taken over by fast-growing weed species. Diligent weed control measures are needed if this method of planting is used. 

The best time to establish bahiagrass is during the spring or early summer month. This enables the grass to grown in before cooler weather begins, when growth is reduced. Seed may safely be sown until later in the year, but growth will again be greatly reduced in the fall. When establishing any grass, it is important to irrigate more frequently than usual. Until a viable toot system is established, turf demands for irrigation are greater. It is also important not to mow a new established lawn until the roots have had a chance to work down into the soil and establish themselves. 

Proper site preparation before planting is critical to ensure successful establishment. Refer to the Edis publication "Preparing to Plant a Florida Lawn" LH012 for complete information. 

Fertilization

Proper fertilization of any lawn-grass is an important component of the best management practices for your home lawn. Fertilization and other cultural practices influence the overall health and quality of your lawn and will reduce its vulnerability to numerous stresses, including weeds, insects, and disease. It is advisable for homeowners to have soil tests done annually. Your local Cooperative Extension Service office has instructions and supplies for taking soil samples and submitting them to the Extension Soil Testing Laboratory for analysis. In particular, phosphorous levels are best determined by soil testing. Since many Florida soils are high in phosphorous, little or no phosphorous may be needed for satisfactory lawn growth after establishment. Established bahiagrass lawns have relatively low fertility requirements. As with any lawn-grass, do not apply more than 1/2 lb of water-soluble nitrogen per 1000 square feet at any one time. Up to 1 lb of nitrogen per 1000 square feet may be applied at one time, but at least 50% of that nitrogen should be in a slow-release form. In general, two weeks following spring regrowth, apply a complete fertilizer such as 16-4-8 at the rate of ½ (water-soluble) to 1 (slow-release) pound of nitrogen per 1000 square feet. The three numbers on the fertilizer bag refer to the percentages of nitrogen, phosphorus, and potassium, respectively. For example, a 50-pound bag of 16-4-8 contains 16% nitrogen or 8 pounds total nitrogen. This bag will fertilize 8000 square feet at the rate of 1 pound of nitrogen per 1000 square feet.

University of Florida guidelines for lawn-grass
fertility show a range of fertilizer rates over which a particular species may be successfully grown for various areas of the state. These ranges are included to account for individual homeowner preferences for low-, medium-, or high-input grass. Additionally, localized microclimatic effects can have a tremendous effect on turfgrass growth, and a range of rates allows for these environmental variations. An example of this would be a typical home lawn that is partially shaded and partially sunny. The grass growing in the shade should receive lower rates of fertilizer than that growing in full sun. The guidelines are also separated into three geographical locations statewide as indicated in the table below. All rates are in pounds of nitrogen per 1000 square feet. For questions on how and when to apply these amounts, refer to the Edis publication EP055, "Fertilizer Recommendations for Your Florida Lawn."

Table 2. Recommended fertility rates for Bahiagrass throughout Florida

Fertilizer should be applied to bahiagrass in two
to four applications from spring green-up through
fall. Do not apply nitrogen too early in the growing
season, particularly in North Florida, or subsequent
frosts may damage the grass. Likewise, don't fertilize too late in the year, as this can slow regrowth the following spring. If you apply water-soluble forms at the lower application rate, it will take more applications to apply the total amount of fertilizer needed for the year than if you apply a slow-release fertilizer form. One of the disadvantages of bahiagrass is its tendency to yellow because of iron deficiency. This problem can be overcome by using a complete

fertilizer, which contains iron, or by addition of a
separate iron material. Soluble iron sources that can be used include ferrous ammonium sulfate, ferrous sulfate, and various iron chelates. Avoid oxide forms of iron, as they will be much less effective than sulfates or chelated forms in alleviating iron deficiency. Apply ferrous sulfate at the rate of 2 ounces in 3 to 5 gallons of water per 1000 square feet. This can be applied evenly and easily with a hose-end applicator. Follow chelated iron label directions if using one of these materials. Iron applications every 6 weeks will help maintain green color and, unlike nitrogen, will not promote excessive top growth. Many cases of iron deficiency occur in soils with pH greater than 7.0. An alternative method of alleviating iron deficiency is to lower the soil pH to 6.0. This can be done by use of ammonium nitrogen fertilizer
sources (e.g., ammonium nitrate or ammonium sulfate) or by application of elemental sulfur before bahiagrass establishment. Elemental sulfur applied at 10 pounds per 1000 square feet will provide a short-term pH reduction. Once the grass is established, up to 5 pounds of elemental sulfur may be added per 1000 square feet if it is immediately irrigated in to prevent burn.

Mowing

Proper mowing practices are necessary to keep
any lawn healthy and attractive. During times of
active growth, bahiagrass should be mowed every 7 to 14 days at 3 to 4 inches of height. Higher mowing heights promote a deeper, more extensive root system that enables the grass to better withstand drought stress. Remove no more than 1/3 of the height of the leaf blades with any mowing (e.g., for a lawn to be maintained at 3 inches in height, mow when the turf reaches 4 to 4 1/2 inches). It is important not to mow bahiagrass at lower heights, as that will reduce the tolerance of the grass to heat, drought, and other stresses. It will also suppress root growth. As bahiagrass does not grow extremely tall, mowing cycles are often dictated by seedhead production. Clippings should be left on the ground after mowing. They do not contribute to thatch buildup, as is often assumed, but are actually readily degraded by microorganisms. They also provide a source of nutrients to the lawn and can reduce fertility requirements if regularly left on the lawn. A sharp, heavy-duty rotary mower blade is needed to cut bahiagrass. Because bahiagrass leaves are very tough, the mower blade will have to be sharpened frequently to ensure a good, clean cut. If this is not done, the leaves may be torn by the mower blades, which can compromise both the health and the appearance of the lawn.

Watering

Irrigating as needed is the best way to water any
established, mature grass, as long as the proper
amount of water is applied when needed. Irrigation is
needed when leaf blades begin to fold up, wilt, or turn
blue-gray in color, or when footprints remain visible
after walking on the grass. Apply 3/4 to 1 inch of
water per application. This will apply water to
roughly the top 8 inches of soil, where the majority of
the roots are. To determine the amount of irrigation
supplied by a sprinkler system, place several coffee
cans throughout the irrigation zones to find out how
long it takes to apply the recommended amount of
water. During prolonged droughts, irrigation may be
needed more often. Bahiagrass has the best drought
tolerance of all lawngrasses grown in Florida and will
usually recover from severe drought injury soon after
rain or irrigation. It is very important not to overwater
Bahiagrass lawns as this weakens the turf and
encourages weeds. During extended periods of
drought, bahiagrass may go dormant if left without
irrigation. The grass will turn brown and stop
growing during this dormant period, but will revive
and resume growth upon regular application of water.
Refer to the Edis publication LH025, "Watering Your
Florida Lawn," for additional information.

Information provided by the University of Florida's IFAS Extension