Bahia grass for Florida lawns

Paspalum notatum - Bahaigrass.jpg

Bahia grass (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.

Bahia grass is a popular low-maintenance lawn-grass for infertile soils. Although bahia grass 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

Bahia grass 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

Bahia grass 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. Bahia grass 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 bahia grass, there is little tolerance for cold temperatures in this species. 

Leaves of bahia grass 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.

Bahia grass displays an open growth habit, which can result in encroachment of weeds into sparse areas. In addition, bahia grass 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 bahia grass available for home lawn or utility use. These may all be established by seed or sod. 

Common

Common Bahia grass is a coarse-textured, light-colored bahia grass. 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 bahia grass. it has good insect and disease resistance and tolerates cold temperatures well.

Pensacola

Pensacola bahia grass was selected in Pensacola, Florida in 1935 and is the most widely grown bahia grass 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 bahia grass. 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 Bahia grass

Establishment

Bahia grass can be established as sod or seed. Advantages of planting a bahia grass 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, Bahia grass 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 bahia grass is not typically recommended. Because of the slow growth habit of bahia grass, 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 bahia grass 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 bahia grass 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 micro-climatic effects can have a tremendous effect on turf grass 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 Bahia grass throughout Florida

Fertilizer should be applied to bahia grass 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 bahia grass 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 bahia grass 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, bahia grass 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 bahia grass 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 bahia grass does not grow extremely tall, mowing cycles are often dictated by seed head 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 bahia grass. Because bahia grass 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. Bahia grass has the best drought tolerance of all lawn grasses grown in Florida and will usually recover from severe drought injury soon after rain or irrigation. It is very important not to over water Bahia grass lawns as this weakens the turf and encourages weeds.

During extended periods of drought, bahia grass 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