March 19, 2008
 
University of Arkansas, Division of Agriculture, Cooperative Extension Service

Turfgrass Science Program (http://turf.uark.edu/) – Turf Tips

1. Buyer beware!

Caveat emptor is Latin for "Let the buyer beware".

There are some products currently being sold in Arkansas that promise to do more for your turfgrass and soil health than they can deliver. Products that sound too good to be true, likely are.

If you are skeptical about whether or not a product will work do the following:
a. Ask to see university research comparing the product to other commonly used products or practices that have a similar purpose. For example, if a product promises to improve rooting, ask for data verifying that the product actually increases turfgrass rooting.
b. Ask also to see a refereed journal article highlighting the practice and verifying its efficacy.

If you verify that a product is effective in some areas of the country, ask for additional data indicating that it will also work well in Arkansas on your turf species and your soil type.

2. Rain gardens and turf

There has recently been increased interest in the use of rain gardens to reduce water runoff in Arkansas and nationally. A rain garden is a specially constructed area with a berm, planted with various plants, and designed to capture rain water from the roof of a house or building. Rain gardens fill with water after a significant rainfall event and the water slowly filters through the soil rather than running directly into a storm drain. The idea is that by capturing the rain water, it is possible to reduce storm water runoff and help protect the environment by recharging ground water, reducing flooding, etc. More information about Arkansas rain gardens can be found at the following link http://ppc.uaex.edu/storm_water/NWAR/NWA_raingardens.pdf and http://ppc.uaex.edu/storm_water/NWAR/NWA_native_plants.pdf .

Traditionally, turfgrass is not often recommended for rain gardens and instead native plants and wild flowers are commonly planted in these gardens. Some articles even state or imply that turfgrass on lawns has a negative impact on water quality. The research on this subject states just the opposite. Turfgrass is often used on farms and in urban areas to trap sediment and reduce runoff in efforts to improve water quality. Research on turfgrass systems states that there is less runoff and sediment loss after rainfall from lawn areas compared to bare soil, shredded mulch and simulated urban forests, and that there is less runoff from turf than from prairie vegetation and crops. Turf affects the overland flow process of water to such a degree that runoff is from lawns insignificant and infrequent. Pesticide and nutrient concentrations in runoff from turf are low because most chemicals applied to turfgrass are trapped within the leaf, thatch and rootzone areas and do not contaminate water supplies. Despite some of this evidence, turf is not commonly used in rain gardens. Recent research out of the university of Wisconsin-Madison has documented the successful use of turf in rain gardens.

The following is a summary of some research at the University of Madison-Wisconsin. There finds were “Urbanization has led to an increase in impervious surfaces that indirectly feed surface waters with potentially pollutant-laden water and reduce groundwater recharge. By using a landscaped garden in a shallow depression, a rain garden, that receives storm water from a rooftop, homeowners may be able to decrease the negative impacts that rooftops have on urban waters. This study investigated whether the presence of berms, type of vegetation, or combination of the two decreases runoff and increases groundwater recharge. Treatments included: 1) Kentucky bluegrass with a berm, 2) Kentucky bluegrass without a berm, 3) native mixture with a berm, and 4) native mixture without a berm, and they were planted in October 2005. Each plot had a separate rooftop, lysimeter, and runoff weir. Runoff and leachate volumes and samples were collected as appropriate. All samples were analyzed for NO3, NH4, total P, and dissolved P. Runoff samples were also analyzed for total suspended solids. After one year of data collection, both bermed treatments significantly reduced the amount of runoff and increased the amount of leachate when compared to both unbermed treatments. The unbermed native mixture treatments produced over two times more runoff than did the unbermed Kentucky bluegrass treatments. Water quality and use were similar for turf and native plants. These results indicate that the presence of a berm appears to be the major determining factor behind rain garden effectiveness, regardless of vegetation type.”  Jacob Schneider, John Stier, and Doug Soldat, University of Madison-Wisconsin – originally published in Golf Course Management – March 2008.

Hopefully, this research will encourage more to use turf in rain gardens. The beneficial effects of turfgrass on water quality have been documented in the past and now research confirms that they can successfully be used in rain gardens to reduce runoff and increase the amount of water naturally filtered through the soil.

 

3. Golf and Sports Turf Classic

University of Arkansas Golf and Sports Turf Classic, April 14, 2008, Stonebridge Meadows Golf Club, Fayetteville, AR
     - Help support turfgrass research and undergraduate scholarships for students studying horticulture at the University of Arkansas.
     - Join us for the 9th annual University of Arkansas Golf and Sports Turf Classic golf tournament
     - Sign up at http://hort.uark.edu/golf/golf-tournament.html

 

4. Homeowner: Crabgrass control

Late February to mid-March is the best time to apply a preemergence herbicide for crabgrass control in Arkansas. Although we are nearing the end of this window, it’s probably not too late to apply preemergence herbicides. To be effective, preemergence herbicides must be applied before weeds emerge. Applying too late may miss the early part of the germination window of crabgrass. Warm-season lawns such as bermudagrass and zoysiagrass should be treated with a preemergence herbicide that does not contain fertilizer. Tall fescue lawns can be treated with a preemergence herbicide with fertilizer. These herbicides should be lightly watered into the lawn for best results. As always, read the label. For more information about weed control in home lawns please check out the linked publication : http://www.uaex.edu/Other_Areas/publications/PDF/FSA-2109.pdf

 

5. Professional: Choosing crabgrass and goosegrass control products

The following tables are adapted from Turfgrass Weed Control for Professionals, 2008 written by Dr. John Boyd. This guide supplies information concerning turfgrass herbicides and growth regulators. Hard copies are available from your extension office, or freely available online at http://publications.uaex.edu or http://turf.uark.edu/publications/factsheets/pro.html .

Summarized below is the efficacy of various herbicides on crabgrass and goosegrass (Table 1), which are common summer annual grassy weeds in Arkansas and are often found in golf courses, lawns, and athletic fields. Additionally, information about the turfgrass tolerance of these various herbicides is summarized in Table 2. This is just one example of the information contained in the 2008 version of Turfgrass Weed Control for Professionals.

Table 1. Efficacy of preemergence herbicides on crabgrass and goosegrass control.

Herbicides

Crabgrass

Goosegrass

atrazine (Aatrex)

F

P

benefin (Balan)

G

F

benefin + oryzalin (XL)

E

G

benefin + trifluralin (Team)

G

F

bensulide (Bensumec, PreSan)

G

F

bensulide + oxadiazon (Goosegrass/Crabgrass)

E

G

dithiopyr (Dimension)

E

G

fenamirol (Rubigan)

P

P

isoxaben (Gallery)

P

P

metolachlor (Pennant)

F

P

oryzalin (Surflan)

E

G

oxadiazon (Ronstar)

G

E

pendimethalin (Pendulum)

E

G

prodiamine (Barricade)

E

G

pronamide (Kerb)

P

P

rimsulfuron (TranXit)

P

P

simazine (Princep)

F

P

E = Excellent, G = Good, F = Fair, P = Poor.

 

Table 2. Turfgrass tolerance of preemergence herbicides.

Herbicide

Bermudagrass

Centipedegrass

St. Augustinegrass

Tall Fescue

Zoysiagrass

atrazine (Aatrex)

S

S

S

NR

I-S

benefin (Balan)

S

S

S

S

S

benefin + oryzalin (XL)

S

S

S

S

S

benefin + trifluralin (Team)

S

S

S

S

S

bensulide (PreSan)

S

S

S

S

S

dithiopyr (Dimension)

S

S

S

S

S

isoxaben (Gallery)

S

S

S

S

S

metolachlor (Pennant)

S

S

S

S

S

oryzalin (Surflan)

S

S

S

S

S

oxadiazon (Ronstar)

S

NR

S

S

S

pendimethalin (Pre-M)

S

S

S

S

S

prodiamine (Barricade)

S

S

S

S

S

pronamide (Kerb)

S

S

S

S

S

rimsulfuron (TranXit)

S

NR

NR

NR

NR

simazine (Princep)

I

S

S

NR

S

Goosegrass/Crabgrass

S

NR

NR

NR

S

S = Safe at labeled rates on healthy, mature turf. I = Intermediate safety, may cause minor damage to mature, healthy turf. Consider using the lower end of the rate range. Do not apply to turf under stress. NR = Not registered for use on this species.

 

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