Empowering Georgia through UGA Extension
Learn about two new invasive insects, the kudzu bug and the brown marmorated stinkbug, in this webinar presented by Dr. Michael Toews, Associate Professor of Entomology, University of Georgia, Tifton, GA; and Dr. Tracy Leskey, Research Entomologist, USDA ARS Appalachian Fruit Research Laboratory, Kearneysville, WV.
Click here to view the webinar which was presented on September 5, 2014.
For more webinars in this series, see All Bugs Good and Bad 2014 Webinar Series.
Some community gardens have a common area that is available for herb planting or individuals may decide to place them in their plots. Herbs in Southern Gardens by UGA’s Wayne McLaurin and Sylvia McLaurin is a good place to start when thinking about planting herbs. In the garden remember, if you want good flavor, pinch off the budding flowers. (Although, many types of herb flowers are great for pollinators).
You have grown herb plants and now you have a little (or big) herb garden. What do I do with all this stuff? An easy way to begin is to taste the herb and think about the flavor. What foods would be enhanced by that flavor? I like to throw a lot of herbs in tossed salads. Experiment with adding chives, parsley, lavender, thyme, oregano, or basil to tossed salads. Don’t put all of them in at first. Try one or two herbs initially to see what you think of the flavor addition. Later you may be loading up the salad bowl with three or more tasty herbs. Another way to start is to experiment with herbs in omelets. Eggs are a neutral flavor serving as a backdrop for the fresh vegetables and herbs you add. You may be able to add less salt as the eggs are flavored by the herbs.
Soup time is just around the corner, and soups are my favorite for adding herbs. This summer mature chives had to be removed from my garden to allow summer vegetables more space. Having a lot of chives at once was really not a problem. They were quickly washed, chopped, and frozen in small portions for addition into winter soups. Just like big onions these little onions with intense flavor are very good in soups like Beef and Barley, Chicken and Rice, or my favorite Vegetable. Again experimenting with flavors to find your favorite is fun. A guideline to help you begin is in tomato based soups try: basil, oregano, parsley and/or cilantro. For soups with chicken as the base try: thyme, parsley, sage, and or savory.
Like soups, casseroles can be flavored with herbs to your hearts (or taste buds) content. The guidelines for casseroles are similar to those outlined for soups in the paragraph above. These foods are the comfort foods that shout homemade, so make the flavor yours by adding your favorite herbs.
As we approach the winter several popular herbs won’t make it past the first frost. Basil is tender and if you want basil in the winter you will need to dry it. One easy way to dry the plants is to cut the stalks, tie them together and hang them upside down in a dry place. Alternately you can dry the leaves inside individually on wax paper, making sure the wax paper is dry. More sophisticated gardeners use a food dryer/dehydrator for drying herbs. Any way you choose you will be happy in December when you have that flavor.
Oregano, rosemary and thyme plants may survive the winter if weather conditions are favorable. For more information on incorporating herbs in your community garden contact your local UGA Extension Agent. He/she will be able to give you useful information to help you achieve success.
Linda Hlozansky has been a Cobb County Master Gardener since 2009. She is a talented gardener and she cooks as well as she gardens. Her family is very lucky!
Happy gardening!
Bodie Pennisi, Department of Horticulture, UGA
Cool weather is upon us and with it, pansy season! Even though pansies are the mainstay for winter color beds, there are increasingly more plant choices available, providing an exciting palette for landscapers to play with.
The following veggies are used for height, color, texture and vegetative element:
Other flowering winter annuals are:
Perennial plants that serve as foliage accents are:
Deer-resistant plants used as flowering accents are:
The pansies and their cousins, the violas, are the bread and butter of the winter color beds, so let’s take a look at how we can keep them happy and flowering all winter long! First, a few words about each of these:
Planting season starts in October, which usually gives the plants ample time to grow and develop a good root system in favorable temperatures before the winter settles in. This starts with the right foundation – the bed.
If you have existing beds, make sure you remove all plant debris from the summer planting, including any mulch. Get a soil test, which will tell you important information about the existing nutrient levels and the soil pH. Remember that pH controls nutrient availability – too high, and the plants develop deficiencies, too low, and the plants develop toxicities.
Ideal soil pH for pansies should be between 5.4 and 5.8. pH higher than 5.8 can lead to increased incidence of black root rot, a devastating disease on pansies and violas. You should test the soil later in the growing season as well, because pH does change.
Make sure you add organic matter to the bed and till well, 8-12 inches deep. Rake to create a gentle slope and trench the front edge of the bed to help with drainage. If you are making new beds, use the following soil recipe: 60% well-aged compost, 20% gravel (#89), 10% coarse sand, and less than 10% native soil.
To get a better idea of how the planting will appear – pre-set large beds. The recommended spacing for fall planting is 8” on center and 10” on center for spring planting.
Gently remove the plant from the pot by inverting the pot and squeezing the sides to release the root ball. Before you plant, examine the root system. A healthy root system has many fine white roots and is not pot-bound. Brown-colored, water-soaked roots are an indication of disease – you should not plant affected plants.
Make sure you plant at the same level the plants originally grew, not deeper, nor shallower.
Mulch is essential for many reasons – weed control, keeping soil temperatures higher, and preventing soil desiccation. Small-size pine nuggets work very well.
After a thorough watering you should liquid-feed the plants for faster establishment. In addition, top-dress the beds with a slow-release fertilizer to ensure an adequate level of fertility.
Low temperatures will become an issue as winter settles in. Even though the soil in Georgia very rarely freezes (exception in the Mountains), soil temperatures below 45oF causes slow growth due to low uptake of nutrients. Plants stop flowering and appear starving even if high fertility is present in the soil!
When soil temperatures drop below 60 oF, begin a liquid feed program with a formula having at least 50% nitrate nitrogen, such as calcium nitrate, potassium nitrate, or magnesium nitrate. The reason being is that ammonia-based fertilizers are not utilized because the bacteria responsible for converting them to a form that the plant roots can absorb are not as active in temperatures below 60 oF. Applying ammonia fertilizer is not only a waste of money but it can also compromise the health of your pansies and violas.
For best results, apply a standard 15-2-20 formula, high-nitrate pansy formula fertilizer at 4-day intervals through March 15. These formulations also have little effect on soil pH, so nutrient deficiencies are less likely to occur. Fertilization frequency depends on the vigor and performance of the planting – more frequent feeding may be needed when the growth is good. If a period of warm weather occurs, cut back on the liquid feed to avoid foliar stretching during the midwinter, which may result in weak, floppy stems. When fertilizing with liquids, apply enough liquid to saturate soil to a depth of 4- to 6-inches.
Removing frost-damaged flowers and old, faded flowers should be a top priority with pansies; not only for aesthetics but to prevent the onset of seed pods that consume the plant’s energy. This also reduces the changes of fungal blight diseases that feed on old blossoms. Trim lanky shoots periodically to encourage branching, compact growth and improved flowering.
Emphasizing again the soil pH, make sure you test during the season. If the soil pH rises above 5.8, drench at 10-day intervals with either iron sulfate or aluminum sulfate (1 to 3 lbs/ 100 gal) to lower the pH. Lightly rinse plants after application to prevent foliage injury. Continue these corrective treatments until the soil pH drops and stays in the 5.4 to 5.8 range.
Soil temperatures usually are on the rise by March 15, so you can start using fertilizers containing ammonia nitrogen. Use the standard fertility program for summer annuals – 200 ppm 20-20-20 (N-P-K) or a slow release/granular fertilizer during the remainder of the growing season.
It’s that time of year when those in mosquito surveillance and control think fondly of consistently cooler temperatures and eagerly await that first hard frost. Of course, this is already happening in some places up north. We may have to wait a while longer in here in Georgia. But that does bring to mind the question: Where do all the mosquitoes go once the colder weather arrives?
Mosquitoes, like all insects, are cold-blooded creatures. As a result, they are incapable of regulating body heat and their temperature is essentially the same as their surroundings. Mosquitoes function best at 80 F, become lethargic at 60 F, and cannot function below 50 F. In tropical areas, mosquitoes are active year round. In temperate climates, mosquitoes become inactive with the onset of cool weather and enter diapause (hibernation) to live through the winter. Diapause induction also requires a day length shorter than 12 hours light (more than 12 hours dark). All mosquitoes pass through four developmental stages: egg, larva, pupa and adult, and diapause can occur in any of these stages depending on the species.
What, if anything, does this mean for West Nile virus (WNV)? If the mosquitoes are infected with WNV when they enter diapause, it should overwinter with them to be transmitted to birds when the mosquitoes emerge the following spring. Temperature is the crucial factor in the amplification of the virus. Studies in various states have shown that WNV does indeed overwinter in mosquitoes. The virus does not replicate within the mosquito at lower temperatures, but is available to begin replication when temperatures increase. This corresponds with the beginning of the nesting period of birds and the presence of young birds. Circulation of virus in the bird populations allows the virus to amplify until sufficient virus is present in the mosquito populations (and vector mosquito populations are high enough) that horse and human infections begin to be detected.
In the Northeastern U.S., Culex pipiens, the northern house mosquito, is the most important vector species. This species overwinters as an adult, and has been found harboring WNV during the winter months. This mosquito goes into physiological diapauses (akin to hibernation) during the winter months, and while it may be active when temperatures get above 50°, it will not take a blood meal.
Culex quinquefasciatus, the southern house mosquito and the major vector for WNV in Georgia, also overwinters as an adult, and also goes into diapause when winter comes, and it is likely that this mosquito also harbors WNV throughout the winter months. However, the southern house mosquitoes go into more of a behavioral diapause when temperatures are below 50°, and are quite capable of taking a blood meal (and maybe transmitting WNV) when things warm up during the winter, which is not an unlikely occurrence here in Georgia especially as one goes further south. So, although the risk for WNV transmission in the south in the winter months is very low, it is certainly possible.
Alfredo Martinez, Turfgrass Pathologist, J.B. Workman, Graduate Assistant, Crop and Soil Sciences Department and Clint Waltz, Turfgrass Specialist
This Alert is an excerpt from the publication Identification and Control of Spring Dead Spot
Spring dead spot (SDS) is a persistent and destructive disease of bermudagrass in Georgia. The disease is particularly prevalent and damaging in north Georgia, especially in the Piedmont region. However, SDS can be observed throughout the state after harsh winters and in areas where bermudagrass has been exposed to freezing temperatures for extended periods of time. The disease has also been observed in zoysiagrass, although less frequently.
Symptoms
As turfgrass “greens up,” well-defined circular patches of dead, bleached-out grass are noticeable in affected areas (Figure 1). Non-infected bermudagrass resumes growth, accentuating the infected areas. Sharp edges between dead and healthy grass are observed once turfgrass greens up in spring. (Figure 2).
Roots, rhizomes and stolons are sparse and dark-colored (necrotic) (Figure 3). Leaves become bleached, gray and straw-colored. Recovery from the disease is slow. Because the turfgrass in affected patches is dead, the primary means of recovery occurs by spread of stolons into the patch. Because recovery is dependent on lateral infill of surrounding bermudagrass, symptoms can remain visible well into the
growing season. If not managed properly, these patches may reappear in the same location the following spring along with weed species that may invade the voids. Patches can get larger year after year.
Disease cycle
The fungi casuing the disease are active in the fall and spring when cool, moist conditions exist. They do not kill bermudagrass directly; instead, they make turfgrass more susceptible to cold and freezing injury by feeding on roots, rhizomes and stolons.
Spread of these fungi primarily occurs through movement of infected plants or infested soil by equipment, people, animals and running water.
Infection of the turfgrass begins when soil temperatures are less than 70 °F. Typically, in Georgia, infection of susceptible grasses begins in late September or early October and will continue as long as soil temperatures are above 50° F. Fungal growth and plant infection can resume at these temperatures in early spring, coinciding with bermudagrass transitioning from winter dormancy (also referred to as “green up”).
Disease Control
Complete control of SDS in a single growing season is uncommon. It typically takes two to four years of proper cultural management and fungicide applications before acceptable control can be achieved. This has led to SDS becoming one of the more difficult diseases for growers to manage on an annual basis.
Resistant cultivars
The primary cultivars grown and used in Georgia (e.g., Tifway, TifSport, Tifton 10, Celebration, etc.) have shown susceptibility to SDS. However, SDS tolerance has been enhanced through breeding. Most “tolerant” cultivars (e.g., Patriot) may still get the disease but not as severely. In general, cultivars with more cold tolerance have less SDS than non-cold tolerant bermudagrasses. On sites where SDS has been a chronic problem, conversion to a tolerant cultivar is an option for disease management.
Cultural practices
Cultural practices that improve the cold-hardiness of bermudagrass can be particularly effective for managing SDS.
Since high nitrogen levels can reduce the winter hardiness of bermudagrass, apply no more than ½ pound of nitrogen per 1,000 ft2 be after mid-September.
Potassium applications in the fall (September or October) that total 1 pound of K2O per 1,000 ft2 can be helpful in improving the winter hardiness of bermudagrass and thus reduce SDS severity. Potassium applications should be applied based on soil test results.
A neutral to slightly alkaline soil pH can increase SDS severity. Maintain soil pH at 5.8 to 6.2. Use acid-forming fertilizers on sites with near neutral to alkaline pH. Apply iron, manganese and other micronutrients based on soil test results.
Any soil condition that reduces bermudagrass root growth such as compaction, excessive thatch (> ½ in) and poor drainage can also increase the severity of SDS. Core aeration and other practices that reduce soil compaction and encourage the production of new roots can be helpful in managing this disease.
Chemical Control
Timing, selection and application of fungicides are important for preventative management of SDS. Research has shown that one application of fungicide in the fall when soil temperatures are between 60° and 80° F provides the best control of SDS. When disease pressure is high, growers may want to make two applications. If a second application is necessary, it should be made four to six weeks after the first application when soil temperatures remain between 60° and 80° F. For complete meteorological information, see GeorgiaWeather.net . For improved results, it is recommended that fungicides be applied at high spray volumes (> 5.0 gal / 1,000 ft2) and/or immediately watered-in.
There have been mixed results from turfgrass managers around the state regarding chemical control of SDS. Those who have seen good results say they spray preventative fungicides that target SDS each year and have been doing so for several years. Therefore, it is important to keep in mind that controlling SDS takes time and control usually cannot be obtained in a single season.
A complete list of fungicides, formulations and product updates for SDS can be found in the annual Georgia Pest Management Handbook and the Turfgrass Pest Control Recommendations for Professionals . Some fungicide options are exclusively for golf course settings. Always check fungicide labels for specific instructions, restrictions, special rates, recommendations, follow-up applications and proper handling.
This article is an excerpt from a more complete publication which can be found here.
For years, bedbugs have been turning up in sometimes odd and random places, such as subways, movie theaters, dressing rooms and schools, but scientists believed that to flourish, the insects would need more frequent access to human blood meals.
Turns out they don’t.
A new University of Florida study, published online this month by the journal Medical and Veterinary Entomology, shows the blood-sucking insects can do much more than survive — they can even thrive — with far less access to human blood than previously believed.
The three-year study also found that it takes only about 11 weeks for one pair of bedbugs to spawn a large enough population to cause harmful blood loss in a baby, and just under 15 weeks for adult humans.
Fire Ants are a hazard in any vegetable garden. They can do some damage to food crops, maybe the occasional nibble in a potato or pea pod. The biggest problem is the damage they can do to gardeners! The ant stings are painful and can be a serious medical issue.
Entomologists agree that fire ants came in to this county through Mobile, Alabama in the early 1900s. Today, the red imported fire ant (Solenopsis invicta), black imported fire ant (Solenopsis richteri), and their hybrids are what we have to deal with. See the UGA Publication Stinging and Biting Pests for more background information.
Fire ant stings are so painful because the ant’s mandibles allow the insect to grab on to the victim as the ant stings. The stinger can be used more than once and afterwards the insect is not impacted and goes on to live another day.
Ants do prey on some garden pests, like caterpillars. However, they also assist other damaging insects like aphids by keeping natural enemies away.
Controlling fire ants in the community garden can be a challenge. It takes an on-going approach and the use of several methods, real integrated pest management(IPM).
Fire ants like full sunshine, just like your vegetable plants. However, they don’t tend to stay in areas that are disturbed. Garden plots that are frequently worked or compost piles that are frequently turned aren’t the ants first choice of habitat.
Some publications recommend pouring boiling water over the mounds. A supply of boiling water would be hard to come by in a community gardening setting. Also, it could be a real danger to the gardener and the vegetable plants. Digging out the mounds is also sometimes recommended. This could create very angry ants that would be inclined to attack the digger.
Fall is a good time for chemical controls. Products containing carbaryl (Sevin), pyrethrins, and pyrethrins plus diatomaceous earth are approved for use in vegetable gardens and will kill fire ants. Be aware these products are not selective and will affect other insects as well. READ THE LABEL of any product you use and follow those directions.
Controlling Fire Ants in the Vegetable Garden, a Clemson University publication, discusses bait products approved for use in the home vegetable garden. Products containing spinosad or pyriproxyfen can be effective when used according to label instructions. Spinosad effects the ant’s nervous system and is considered fast acting. Pyriproxyfen prevents the development of worker ants. Products containing these ingredients include Conserve and Esteem. Be sure to place bait around the mound and not on top of the mound for the most effective use.
Using baits in the surrounding lawn or grass area can also be helpful. With any chemical product, read the label and make sure it is approved for the use you need. Do NOT use a product in the vegetable garden unless it is labeled for use in the vegetable garden. See the UGA Pest Management Handbook for more information on chemical control. UGA’s Dan Suiter is the leader of the Urban Pest Management Program and they do research on fire ant control.
The bottom line – fire ants are not easy to control. It takes diligence and a combination of approaches. Contact your local UGA Extension Agent for the latest information on dealing with fire ants.
Happy Gardening!
Patrick McCullough, Extension Weed Specialist, University of Georgia
Annual bluegrass (Poa annua L.) is a problematic winter annual weed. Compared to most turfgrasses, annual bluegrass has a lighter green color, coarser leaf texture, and produces unsightly seedheads. Contrary to its name, both annual (live for one season) and perennial (live for many seasons) populations of annual bluegrass may be found in turf. Perennial plants are more prevalent on closely mowed turf that receives frequent irrigation and high nitrogen fertilization. These populations are more prevalent in shady or highly trafficked areas with compacted soil. Annual plants are more upright in growth and produce more seed than lower-growing perennial types.
Annual bluegrass seed germinates in late summer/early fall once soil temperatures fall below 70° F. Seedlings grow and mature in fall, overwinter in a vegetative state, and produce seed in spring. Annual bluegrass is a prolific seed producer and individual plants may produce hundreds of viable seed, even when closely mowed. Annual bluegrass flowers over several months in spring and produces seed that may remain dormant in soil for years before germinating. Annual bluegrass grows well under short day lengths and cool conditions, and may out-compete other turf species during late fall and early spring. Annual bluegrass often dies from summer stresses but may survive if irrigated and pests are adequately controlled, especially for perennial biotypes.
Cultural Control
Several cultural practices can be utilized to control annual bluegrass. Deep and infrequent irrigation encourages turfgrass root development which improves the ability of desired grasses to compete with annual bluegrass in mixed stands. Withholding water until desirable turfgrass species exhibit initial drought stress symptoms can help reduce soil moisture for potential annual bluegrass infestations. Overwatering, especially in shady areas, may predispose the site to annual bluegrass invasion.
Practices that promote soil compaction should be avoided to promote turfgrass growth and competition with annual bluegrass populations. Core aerifications should be conducted during active turf growth and favorable periods for quick recovery. Voids left in turf with exposed soil following aerifications may permit annual bluegrass invasion during periods of peak germination. For cool-season grasses, fall aerfications should be timed before annual bluegrass germinates. Warm-season grasses should have enough time to recover from summer aerifications to promote dense, high quality turf prior to annual bluegrass germination in fall.
Nitrogen fertilization should be reduced during peak annual bluegrass germination and periods of vigorous growth. High nitrogen at these times encourages annual bluegrass spread and survival in to winter and spring. Fertilizing dormant turfgrasses when annual bluegrass is actively growing may also exacerbate infestations and should be avoided.
Mowing height, frequency, and equipment requirements vary among turfgrass species and practitioners should maintain turf under appropriate regimes for successful long-term culture (Table 1). Raising the mowing height during peak annual bluegrass germination may encourage turf competition to reduce potential infestations. Lower mowing heights may predispose turf to stress and reduce competition with annual bluegrass populations. Turfgrass should also be mowed frequently during periods of vigorous growth to prevent scalping. Scalping thins out turf and may enable weeds, such as annual bluegrass, to establish. While returning clippings is recommended to recycle nutrients to the soil, removal of clippings may be useful when annual bluegrass is present and producing seedheads. Removal of clippings at this time will reduce the spread of viable seed.
Chemical Control
Preemergence Control
Preemergence herbicides may prevent annual bluegrass seed germination. However, preemergence herbicides will not eradicate established plants and will not effectively control perennial biotypes of annual bluegrass from spreading vegetatively. Application timing of preemergence herbicides for annual bluegrass control is very important. Herbicides must be applied in late summer/early fall before annual bluegrass germination. A second application can be applied in winter to control later germinating plants. Fall applied preemergence herbicides should not be used if reseeding or resodding is needed to repair areas of damaged turf within several months after herbicide applications.
Several preemergence herbicides used for summer annual weed control will effectively control annual bluegrass in fall and winter (Table 2). Fall applications of herbicides such as bensulide (Betasan), dithiopyr (Dimension), flumioxazin (Sureguard), oxadiazon (Ronstar, Starfighter), pendimethalin (Pendulum, others), and prodiamine (Barricade, others) may effectively control annual bluegrass. Indaziflam (Specticle) provides excellent preemergence control of annual bluegrass and also provides early-postemergence control as well. Indaziflam is only labeled in warm-season turfgrasses but may provide greater application timing flexibility than dinitroaniline herbicides in fall.
Combination herbicide products are also available which may improve efficacy of applications. These products include oxadiazon plus bensulide (Anderson’s Crab and Goose), oxadiazon plus prodiamine (Regalstar), and benefin plus oryzalin (Team 2G or Team Pro). Many preemergence herbicides are available under a wide variety of trade names and formulations and turf mangers should carefully read label directions before applications.
Atrazine (Aatrex, Purge, others) and simazine (Princep, WynStar, others) are labeled for centipedegrass, zoysiagrass, St. Augustinegrass and bermudagrass. Atrazine can be applied to actively growing and dormant centipedegrass or St. Augustinegrass but bermudagrass can be injured if treated while actively growing. Both herbicides have excellent preemergence activity on annual bluegrass but soil residual is generally shorter (four to six weeks) compared to aforementioned herbicides. Several atrazine products are restricted use pesticides and turf managers should check labels for further information before use.
Mesotrione (Tenacity) is labeled for use in centipedegrass, perennial ryegrass, St. Augustinegrass (sod production only), tall fescue, and dormant bermudagrass (Table 2). Mesotrione may be applied during establishment of these grasses (except bermudagrass) and effectively controls annual broadleaf and grassy weeds. Preemergence applications of mesotrione control or suppress annual bluegrass but postemergence use is ineffective for control of established plants. Mesotrione may be applied in tank-mixtures with atrazine or simazine on centipedegrass to improve efficacy of applications.
Most preemergence herbicides will provide similar initial efficacy if applied before annual bluegrass germination and sufficient rain or irrigation is received. Preemergence herbicides require incorporation from irrigation or rainfall so that weeds may absorb the applied material. In order to effectively control annual bluegrass, preemergence herbicides must be concentrated in the soil seedbank. Retention on leaf tissue can be avoided by irrigating turf immediately after application for effective soil incorporation and herbicide activation.
Preemergence herbicide applications on non-irrigated sites have less potential for residual control, compared to irrigated turf, from product loss, poor soil incorporation, and failure to activate the herbicide. Practitioners should return clippings on non-irrigated sites to help move potential herbicides remaining on leaf tissue to the soil. If clippings are collected as part of routine maintenance, practitioners should consider returning clippings until at least half to one inch of rainfall is received. Granular products may also be applied to non-irrigated sites for better soil incorporation than liquid formulations. Granular products may be easier to handle and apply with less equipment necessary than sprayable formulations. Granular herbicides should be applied when morning dew is no longer present to avoid interference from leaf tissue.
Postemergence Control
Annual bluegrass may be selectively controlled with postemergence herbicides (Table 3). Practitioners managing warm-season grasses have more options for selective postemergence annual bluegrass control than cool-season grasses. Flazasulfuron (Katana), foramsulfuron (Revolver, Tribute Total), rimsulfuron (TranXit), and trifloxysufluron (Monument) are labeled for bermudagrass and zoyiagrass non-residential commercial lawns and other sites. Flazasulfuron and rimsulfuron are also labeled for use in centipedegrass. Efficacy of these herbicides generally increases under warm temperatures in spring compared to winter and non-ionic surfactants may enhance efficacy.
Pronamide (Kerb) is a restricted use herbicide for annual bluegrass control in non-residential bermudagrass, centipedegrass, St. Augustinegrass, seashore paspalum, and zoysiagrass. Pronamide is root-absorbed and must be watered in following applications. Pronamide efficacy is generally slower than most sulfonylureas and activity for annual bluegrass control may take approximately four to six weeks.
Atrazine (Aatrex, Bonus S, others) and simazine (Princep, WynStar, others) may also be applied to bermudagrass, centipedegrass, St. Augustinegrass, and zoysiagrass for selective postemergence annual bluegrass control. These herbicides often provide erratic control of annual bluegrass but may control other grassy and broadleaf weeds. Actively-growing bermudagrass is sensitive to atrazine and applications are recommended only during the late fall and winter months.
Dormant bermudagrass may be treated with nonselective herbicides, such as glyphosate (Roundup, Touchdown, others), glufosinate (Finale), and diquat (Reward). These herbicides will injure or kill existing vegetation, including annual bluegrass and managers should only spray at peak dormancy when no green turfgrass foliage is observable. Nonselective herbicides should only be applied to completely dormant bermudagrass and applications during early spring may delay greenup with significant turf injury. Flumioxazin (Sureguard) is a new herbicide for pre- and postemergence annual bluegrass control but applications are limited to dormant bermudagrass only. Flumioxazin use after greenup or on other species are not recommended due to excessive injury potential.
Selective annual bluegrass control options in cool-season lawns are limited. Ethofumesate (Prograss) has controls established annual bluegrass in perennial ryegrass, tall fescue, and dormant bermudagrass (Table 5). Two or three ethofumesate applications may be applied in late fall at three to four week intervals. Annual bluegrass control may be seen that fall, but control is usually observed the following spring. Annual bluegrass control with ethofumesate may vary greatly over years depending on environmental conditions. Amicarbazone (Xonerate) is a new Photosystem II inhibitor, similar to triazine herbicides, but may be used in tall fescue lawns and other cool-season grasses. Applications of amicarbazone in Georgia are limited to springtime only to minimize injury to cool-season grasses. Warm-season turf is very tolerant to amicarbazone and may be treated at any seasonal timing.
Bispyribac-sodium (Velocity) has shown potential for selective annual bluegrass control in tall fescue and perennial ryegrass lawns. However, this herbicide is currently registered for creeping bentgrass and perennial ryegrass on golf courses and sod farms only. Spot treatments of nonselective herbicides are generally the most effective treatment regime for annual bluegrass control in cool-season grasses.
Managing Herbicide Resistance
Annual bluegrass is a genetically diverse species and various biotypes present in turf may have differential responses to herbicides. Repeated use of one herbicide chemistry may effectively control annual bluegrass but resistance may develop in local populations if herbicides with different modes of action are not incorporated in to management regimes. Herbicide resistance is the survival of a segment of the population of weeds following a herbicide dosage lethal to the normal population. Resistance occurs from repeated use of the same herbicide or mode of action over years and may be a concern with problematic annual weeds, such as annual bluegrass.
Triazine herbicides, atrazine and simazine, have been repeatedly used for years due to the wide spectrum of weeds controlled as pre- or postemergence treatments in warm-season grasses. Resistance in weed populations has been reported with these herbicides which may contribute to inconsistent efficacy for annual bluegrass control in turf. Resistance to sulfonylureas has been reported in weed populations in agronomic crops and repeated use in turfgrasses may also contribute to resistance in annual bluegrass populations.
Preemergence chemistries, such as the dinitroanalines, may have resistance among weed populations from repeated use over years. Turf managers should rotate preemergence herbicides from mitotic inhibitors to other modes of action to minimize resistance in annual bluegrass populations. Herbicides to consider in rotation programs from dinitroanilines would include indaziflam, ethofumesate, or oxadiazon. These chemistries offer a different mode of action than dinitroanilines but cost, label restrictions, and turfgrass tolerance may be limiting factors for using these products. Combination herbicides are also available, such as oxadiazon + prodiamine (Regalstar), oxadiazon + bensulide (Anderson’s Crab and Goose), and prodiamine + sulfentrazone (Echelon), with more than one mode of action that effectively control annual bluegrass in turf.
Table 1. Mowing requirements for commercial turfgrasses.
| Mowing Requirements for Turfgrasses | |||
| Species | Mower Type | Height (inches) | Frequency (days) |
| Bermudagrass | |||
| Common | Rotary/reel | 1 to 2 | 5 to 7 |
| Hybrid | Rotary/reel | 0.5 to 1.5 | 3 to 4 |
| Centipedegrass | Rotary | 1 to 2 | 5 to 10 |
| Perennial Ryegrass | Rotary/reel | 0.5 to 2 | 3 to 7 |
| St. Augustinegrass | Rotary | 2 to 3 | 5 to 7 |
| Tall Fescue | Rotary | 3 | 5 to 7 |
| Zoysiagrass | Reel | 0.5 to 2 | 3 to 7 |
Table 2. Efficacy of preemergence herbicides for annual bluegrass control in commercial turfgrasses.
| Common Name | Trade Name (Examples) | Efficacy |
| atrazine | Aatrex, various | E |
| benefin | Balan, others | E |
| bensulide | Betasan, others | F |
| dithiopyr | Dimension | G |
| ethofumesate | Prograss | G-E |
| flumioxazin | Sureguard | G |
| indaziflam | Specticle | E |
| mesotrione | Tenacity | F |
| oryzalin | Surflan, others | G |
| oxadiazon | Ronstar, others | G |
| pendimethalin | Pendulum, others | G |
| prodiamine | Barricade, others | E |
| pronamide | Kerb | E |
| simazine | Princep, others | E |
E = Excellent (90 to 100%), G = Good (80 to 89%), F = Fair (70 to 79%), P = Poor (<70%).
Table 3. Efficacy of postemergence herbicides for annual bluegrass control in turfgrass.
| Common Name | Trade Name (Examples) | Efficacy |
| amicarbazone | Xonerate | F-G |
| atrazine | Aatrex, others | E |
| bispyribac-sodium | Velocity | F-G |
| flazasulfuron | Katana | G-E |
| flumioxazin | Sureguard | F-G |
| foramsulfuron | Revolver | E |
| glufosinate | Finale | E |
| glyphosate | Roundup, others | E |
| imazaquin | Image | P-F |
| metribuzin | Sencor | G |
| pronamide | Kerb | E |
| rimsulfuron | Tranxit | E |
| simazine | Princep, others | G-E |
| thiencarbazone + foramsulfuron + halosulfuron | Tribute Total | G-E |
| trifloxysulfuron | Monument | E |
E = Excellent (90 to 100%), G = Good (80 to 89%), F = Fair (70 to 79%), P = Poor (<70%).
Alfredo Martinez, UGA Plant Pathologist and Willie Chance, UGA Center for Urban Agriculture
This year did your lawns show round or irregular dead or dying patches? Did the grass yellow or wilt even though the soil is moist? If so, these lawns may be infected with Take All root rot. This fungal disease affects centipede, St. Augustine and Bermuda lawns
The fungus causing Take-All rots the lawn’s roots and aboveground runners (stolons).
To identify the disease look for:
This fungus prefers cooler weather – infecting lawns in the fall, growing through the winter and slowing growth in late spring. Much damage from this disease is done in the fall and spring. By the time we see disease symptoms (often in early spring and summer), the harm is done. Damage can be mistaken for green up problems. Expect the disease to be less active as temperatures increase.
Since this disease destroys roots, lawns may be slow to recover. Affected lawns are more susceptible to other stresses, like herbicides and drought. Turf may not show evidence of the disease on the leaves until turf is stressed. For instance, a lawn with an unnoticed case of Take-All may be damaged or killed by the stress of a normal herbicide application. This can reflect poorly on the pesticide applicator.
Fall is the best time to control this disease. The best control is to improve cultural practices to prevent the disease and to increase the vigor of the grass so that it will recover quickly. To slow disease progress:
Apply fungicides in September and again in October for best disease prevention. In warmer months, a fungicide may help, especially if sodding or plugging turf into affected areas. However, fall applications are best at controlling this disease. Fall applications should prevent the need for spring applications and should reduce Take-All damage in affected lawns and improve spring turf vigor.
For pesticide recommendations see the UGA publications – Pest Management Handbook or Turfgrass Pest Control Recommendations for Professionals
For more information on controlling Take All see Turfgrass Diseases in Georgia or Enfermedades de los céspedes en Georgia
The Stone Mountain Community Garden is a beautiful space located on an old ball field. It is a partnership between the city of Stone Mountain and UGA Extension Master Gardeners. When you first visit you will be impressed with the number of plots (50) and how well organized and maintained the raised bed plots are. One master gardener site coordinator, Averil Bonsall, indicated that they have public demand for more but they are trying to keep it a manageable size. You will also notice the wildlife! A bee hive ensures that bees are present and they are busily flying around collecting nectar and pollinating the gardens which are full of vegetables, fruits and flowers. Birds and pollinators are also attracted by the new meadow garden on the perimeter of the property and the sunflowers.
The garden has demonstration areas where gardeners can learn how to grow herbs and fruits. A demonstration compost bin system is on the property and is used by the gardeners. There is a 3,000 square foot pantry garden where everyone pitches in with the chores and the food is donated to the local food pantry in Stone Mountain.
To be part of the garden each grower pays a small annual fee and commits to provide two four-hour time periods of labor in the community areas of the garden. This can be mowing the grass,working in the pantry garden, or weeding the demonstration areas. As with all gardens, there is always a lot to be done.
The usual tomatoes, beans, and squash, are present as well as some unusual choices. There is a large asparagus bed and a plot of dwarf okra. Tomatoes are grown in hay bales here and there is an ornate trellis for growing pole beans. The growers really do try new things and learn from each other. For a brief walking tour of the garden visit A Walk Through the Stone Mountain Community Garden at VFW Park.
“The garden is a testament to the cultural richness and diversity of the nearby community. Everyone works together and learns from each other. They have put the ‘Community’ back into community gardening.” – Gary Peiffer, DeKalb UGA Extension Agent
Happy Gardening!