Landscape Alerts & Updates | September 2019

September 20, 2019 by Greg Huber

Insufficient production and storage of photosynthates during the fall transition into dormancy can translate to issues during spring green-up. Drought stressed turfgrass in August 2016 (Left) was able to recover prior to dormancy following appreciable rainfall (Right). However, we are seeing drought-stressed turfgrass in September of 2019 and the dormancy transition is quickly approaching. Photo by Clint Waltz, UGA.

Tips for managing drought stressed turfgrass as dormancy approaches

by Clint Waltz

During periods of hot and dry weather, certain modifications to your lawn maintenance practices will help to carry your turfgrass through periods of inadequate rainfall and reduce losses. The height of the warm-season turfgrass growing season spans from May to October. Given average conditions (regular rainfall and moderate temperatures), bermudagrass, zoysiagrass, St. Augustinegrass, centipedegrass, and other warm-season species respond quickly to cultural and maintenance practices such as mowing, fertilizing, aerating, topdressing, and weed management. However, the summer of 2019 has delivered hot and dry weather with sporadic rainfall. With fall approaching, now is the time to adjust your turfgrass management program to promote a smooth transition into dormancy and green-up next spring.

From mid- through late-summer rainfall across Georgia has been variable with some areas receiving timely rain and other areas being droughty. Moisture stress in turfgrasses can be recognized in the early stages by a dull bluish-gray cast. Additionally, take note of footprints and tire tracks in the turf that do not seem to rebound. If you are in an area that has lacked rain, consider applying some irrigation to get the grass growing.

Dr. Clint Waltz, UGA Extension Turfgrass Specialist, suggests these tips for managing turfgrass as it transitions into dormancy:

Raise the cutting height within the recommended mowing range
Do not apply nitrogen containing fertilizers
Modify herbicide programs during high temperatures and moisture stress
Water deeply & infrequently
Grasscycle
Use water conserving and drought tolerant turfgrasses

Raise the Cutting Height

Turfgrass stress can be reduced by using a sharp mower blade and raising the cutting height by 1/2″ or to the tallest allowable height of the recommended mowing range during drought. A clean cut also reduces moisture loss through wounds and minimizes entry points for disease. Taller shoots promote deeper roots and a dense canopy can help to reduce ground surface temperatures and conserve moisture. Grasscycling (mulching clippings versus bagging) can also help to conserve moisture.

Avoid Nitrogen Applications

As grasses move into dormancy they need to “harden-off”. Nitrogen fertilization encourages new shoot growth which directs plant sugars, and other metabolites, away from storage organs (e.g. rhizomes, stolons, and crown). These storage organs and sugars provide the energy for the grass to green-up next spring. By allowing the plant to harden-off and accumulate sugars in the storage structures, the grass is better able to survive winter stresses and recover next year.

Modify Herbicide Programs During High Temperatures and Drought

Many herbicides act upon plant growth processes and can be less effective during periods of drought when weeds are not actively growing. In addition, certain herbicides may cause damage to drought-stressed turf or non-target landscape plants due to volatilization and drift during high temperatures. Review your pesticide labels for specific information regarding temperature requirements, watering requirements, and proper application.

Water Deeply and Infrequently

The optimum watering schedule can be roughly determined by observing the number of days that pass between signs of moisture stress. Apply sufficient water to saturate the root zone to a depth of 6-8 inches. Clay soils and sloped areas may require staggered watering intervals to allow time for water infiltration between cycles and prevent runoff. Irrigating in early morning conserves water by reducing evaporation and drift. A good practice is to align watering schedules with drought management rules so that in the event of a declared drought, the appropriate watering program is already in place. The 2010 Water Stewardship Act permits lawn watering between the hours of 4:00pm and 10:00am.

Use Water Conserving and Drought Tolerant Turfgrass Cultivars

The University of Georgia Turfgrass breeding programs continue to make excellent strides in developing improved cultivars with low water use and high drought tolerance. For new installations or where turfgrass replacement is needed, look for improved cultivars such as TifTuf bermudagrass. Visit www.GeorgiaTurf.com for more information on selecting turfgrasses.

Landscape Alerts & Updates | June 2019

September 20, 2019June 20, 2019 by Greg Huber

Photo by Clint Waltz, UGA.

Nostoc Algae in Turfgrass

Guest post by Clint Waltz, Ph.D., University of Georgia Turfgrass Specialist.
(Turfgrass Blog #4: 2019 Edition, June 10, 2019)

With the recent dry weather encouraging the use, and possible overuse, of irrigation systems then the recent tropical conditions – rainfall and humidity – I have had several pictures and questions about a jelly-like substance growing in the turf. The jelly-like “stuff” is a Nostoc algae,a genus of cyanobacterium formerly classified as blue-green algae. It has multiple common names like star jelly, witch’s butter, and others.

Under warm temperatures Nostoc may appear suddenly in lawns, and other turf areas, following a period of rain and can be an indication of overwatering. In turf, it is generally on a site where the grass is growing poorly due to severe compaction, overwatering, or both. It does not cause turf decline or death; it colonizes areas where it has favorable growing conditions and the grass was already thin. Poor drainage and compacted soils create a favorable environment for Nostoc. It will dry-out if the water or rainfall diminishes but it has only gone into dormancy. With enough moisture, it will come back to “life”.

In its hydrated, gelatinous, green state it can be a safety hazard. It is slippery. Be careful walking on it. However, when it dries-out it can become restrictive to turfgrass growth. Nostoc dries into a black crust that can prevent stolons from rooting, or “tacking”, into the soil, delaying turfgrass growth and spread.

Nostoc can be difficult to control. To discourage its growth, encourage the growth of the grass. Algae is less of an issue with an actively growing turfgrass canopy. The first step is to check the irrigation system to make sure it is watering properly (i.e. not too regular or too much). The turfgrass species we grow in Georgia perform better when grown on the slightly dry side, so scaling back the irrigation and adjusting the irrigation schedule will benefit the grass and can discourage the algae.

Improve internal soil and surface drainage. Core aeration opens the soil, allows oxygen into the root system, and reduces compaction. While allowing the soil surface to dry-out then breaking up the Nostic “crust” by scarifying the upper ¼- to ½-inch can break the algae into pieces and encourage its spread, it also permits the turfgrass stolons to root into thin areas and outcompete the Nostoc. With proper irrigation and core aerification the grass can cover and eventually predominate the area where the Nostoc was present.

For more information on Nostoc Algae, contact your local UGA Extension Agent at 1-800-ASK-UGA1, or click below to find your local office information.

FIND YOUR AGENT

Controlling Moss and Algae in Turf, UGA Extension Circular #823.
https://extension.uga.edu/publications/detail.html?number=C823&title=Controlling%20Moss%20and%20Algae%20in%20Turf

Landscape Alerts & Updates | February 2019

February 24, 2019February 15, 2019 by Greg Huber

Diseases and Problems to Watch for in Winter and Early Spring

Guest Post by Alfredo Martinez

Microdochium Patch in Golf Courses. When night temps dip below 50°F, Microdochium Patch (Fusarium Patch, pink snow mold) can be severe on new bentgrass and semi-dormant bermudagrass greens, and on greens overseeeded with Poa trivialis. Patches begin as small reddish-brown spots that can grow and coalesce into large blighted areas. White to pink mycelium (sometimes mistaken for Pythium or dollar spot) may appear during extended periods of rain and overcast weather. Cultural controls are the same as those listed above for Yellow Patch. Effective fungicides include products that contain azoxystrobin, fluoxastrobin, iprodione, metconazole, propiconazole, pyraclostrobin, thiophanate-methyl, triadimefon, trifloxystrobin, triticonazole or vinclozolin.

Slime Mold/Sooty Mold;Blackening observed in fully dormant zoysia and or bermudagrass after few rain events? We have received samples exhibiting olive green, gray to black molding affecting dormant tissue This condition is known as slime mold and /or “sooty mold” in other crops. The growth is superficial in nature. While the symptoms are worrisome, the condition does not affect turf further. Sooty mold is the result of secondary, saprophytic fungi and not considered a true disease. Sooty mold develops on dormant, senescing and/or damaged turf when prolonged wet, humid weather occurs. This symptomatology is probably going to go away as sunny, breeze weather resumes. This blackening should mow off rather quickly.

Yellow Patch (Rhizoctonia cerealis).Sporadic infections of R. cerealis(yellow patch) have been observed in ryegrass over-seeded bermudagrass turf swards and sport fields. The disease is rare in the state, but it thrives in extended periods of wet, cloudy weather. It is a cool-temperature disease (50 to 65°F). Disease development is significantly suppressed at temperatures lower than 45°F and greater than 75°F. Avoid excessive nitrogen fertilization in the fall or when the disease is present. Thatch management is essential for disease control. Maintain thatch at less than 0.5 inch. There are several fungicides that can be used to control the disease, however in the state, yellow patch usually does not warrant a fungicide application.

Dollar Spot Can Start Early: The dollar spot fungus (Sclerotinia homoeocarpanow named Clarireediasp) can produce infections on warm season grass as soon as they start to green up. Additionally, dollar spot can continue to infect cool season grasses anytime temps are above 50°F but it is fully active between 60°F and 70°F. Due to low temperatures, recovery of turf from dollar spot symptoms in late winter or early spring may take weeks rather than days. Therefore, preventive control of dollar spot is important at this time of the year. Monitoring fertility is an important first step to controlling dollar spot. Excessive moisture on turfgrass foliage will promote dollar spot epidemics. Excessive thatch layers and compacted soil stresses the plants and slows turfgrass growth and recovery from disease.

Chemical control for practitioners: A variety of fungicides are available to professional turfgrass managers for dollar spot control including fungicides containing benzimidazoles, demethylation inhibitors (DMI), carboximides, dicarboximides, dithiocarbamates, nitriles and dinitro-aniline. Several biological fungicides are now labeled for dollar spot control. For a complete and updated list of fungicides available for dollar spot, visit http://extension.uga.edu/publications/detail.cfm?number=SB28

Alfredo Martinez is a University of Georgia Professor and Extension Plant Pathologist in the areas of turfgrass, small grains, and non-legume forages at the Griffin campus.

Brown Patch and Pythium Blight

July 22, 2018 by Alfredo Martinez-Espinoza

Brown patch (caused by Rhizoctonia solani) and Pythium blight (caused by Pythium spp).

These diseases are often the most severe diseases for cool-season grasses, especially on tall fescue and ryegrass.

Pythium blight has the potential to cause significant damage to turfgrass quickly. The disease starts as small spots, which initially appear dark and water-soaked. Affected turfgrass dies rapidly, collapses, and seems oily and matted. White, cottony mycelia may be evident early in the morning. The disease is driven by hot-wet weather, which correlates with increased stress on the turf. Similar environmental and cultural factors that encourage brown patch also promote Pythium. Therefore, cultural practices for control of brown patch will also help to minimize Pythium blight development. A correct diagnosis is essential because Pythium control requires specific fungicides.

Several fungicides are available for each of the diseases described above. Consult the Georgia Pest Management Handbook or the Turfgrass Pest Control Recommendations for Professionals (www.georgiaturf.com) for proper fungicide selection and usage. Read the label and follow proper guidelines.

Pythium blight on tall fescue (Photo Lee Burpee)

Brown patch can cause a foliar blight, which results in necrotic leaves and circular brown patches up to 4-5 ft in diameter. High soil and leaf canopy humidity, and high temperatures increase disease severity. Higher than recommended rates of nitrogen in the spring promotes disease. Management options include: avoid nitrogen application when the disease is active, avoid infrequent irrigation and allow the foliage to dry, mow when grass is dry, ensure proper soil pH, thatch reduction, and improve soil drainage.

Brown patch on tall fescue (Photos Alfredo Martinez)

For more information on Brown patch and Pythium visit http://extension.uga.edu/publications/detail.html?number=B1233

Gray Leaf Spot

July 22, 2018 by Alfredo Martinez-Espinoza

By Alfredo Martinez

Gray Leaf Spot

Figure 1 (left) and 2 (right). Gray leaf spot on St. Augustinegrass (images by Alfredo Martinez)

Gray leaf spot (Figure 2) is a fungal disease that affects St. Augustinegrass, perennial ryegrass and tall fescue in Georgia. The disease is particularly aggressive in St Augustinegrass. Hot, humid summer weather and high nitrogen levels can make turf susceptible to this disease. The fungus causing the disease is Pyricularia grisea.

Symptoms: The symptoms of gray leaf spot vary depending on the grass cultivar. On St. Augustinegrass, gray leaf spot first appears as small, brown spots on the leaves and stems. The spots quickly enlarge to approximately ¼ inch in length and become bluish-gray and oval or elongated in shape. The mature lesions are tan to gray and have depressed centers with irregular margins that are purple to brown. A yellow border on the lesions can also occur. In cool-season turfgrass, the symptoms are similar to those of melting out.

Conditions Favoring Disease: Gray leaf spot is favored by daytime temperatures between 80ºF to 90ºF and night temperatures above 65ºF. It is also found in areas with high nitrogen levels and that are stressed by various factors, including drought and soil compaction. This disease is most severe during extended hot, rainy and humid periods.

Disease Management Tips: Management practices that minimize stress and avoid rapid flushes of lush growth during the rainy season lessen the likelihood that severe gray leaf spot symptoms will develop. If irrigation is used to supplement inadequate rainfall, water infrequently but deeply.

Proper irrigation regimens should protect against symptoms of drought stress without increasing disease pressure by extending periods of leaf wetness. Excessive soil moisture and leaf wetness promote gray leaf spot. Irrigating in the late afternoon or evening should be avoided, as this prolongs periods of leaf wetness.

Proper mowing practices are most important for gray leaf spot management in St. Augustinegrass. This grass must frequently be mowed during the summer months to remove excess leaf tissue and keep the canopy open and dry. Mow the turf at the correct height for the designated turfgrass species and remove only one-third of the leaf blade per mowing. Collecting clippings reduces the spread of the disease when gray leaf spot symptoms are evident. Thatch layers should be removed if they are greater than 1 inch in depth.

St. Augustinegrass is especially sensitive to some herbicides. If possible, manage weeds using cultural management techniques and minimal amounts of herbicides. The timing of any atrazine application should be chosen carefully, as this herbicide can stress the grass, especially when temperatures may climb above 85 degrees F. Atrazine applications made before or during disease-favorable conditions increase the likelihood of severe gray leaf spot symptom development. Spot-treating trouble areas with the herbicide may also be considered. Herbicides should always be applied according to the label instruction

Fungicides are available to control the disease. Consult the current Georgia Pest Management Handbook — www.ent.uga.edu/pmh/.

Landscape Alert – September 2017

November 15, 2017September 12, 2017 by Greg Huber

Fall Turfgrass Disease Prevention and Control

by Alfredo Martinez

Large Patch

Rhizoctonia large patch is the most common and severe disease of warm season grasses (bermudagrass, centipedegrass, seashore paspalum, St. Augustinegrass, and zoysiagrass) across the state of Georgia. Due to spring and fall disease-promoting environmental conditions across Georgia coinciding with grasses leaving and/or entering dormancy, large patch can appear in warm season grasses in various grass-growing settings, including home lawns, landscapes, sports fields, golf courses, and sod farms. Symptoms of this lawn disease include irregularly-shaped weak or dead patches that are from 2 feet to up to 10 feet in diameter. Inside the patch, you can easily see brown sunken areas. On the edge of the patch, a bright yellow to orange halo is frequently associated with recently affected leaves and crowns. The fungus attacks the leaf sheaths near the thatch layer of the turfgrass.

Large patch disease is favored by:

Thick thatch.
Excess soil moisture and poor drainage.
Too much shade, which stresses turfgrass and increases moisture on turfgrass leaves and soil.
Early spring and late fall Nitrogen fertilization.

If large patch was diagnosed earlier, fall is the time to control it. There is a myriad of fungicides that can help to control the disease. Fungicides in the following classes are labeled for large patch control: carboxamides, benzimidazoles, carbamates, dicarboximides, DMI fungicides, di-nitro anilines, control. For a complete and updated list of fungicides available for commercial control of large patch, visit http://extension.uga.edu/publications/detail.cfm?number=SB28 or http://www.commodities.caes.uga.edu/turfgrass/georgiaturf/Publicat/1640_ Recommendations.html. Preventative or curatives (depending on the particular situation) rates of fungicides in late September or early October and repeating the application 28 days later are effective for control of large patch during fall. Fall applications may make treating in the spring unnecessary. Always follow label instructions, recommendations, restrictions and proper handling.

Cultural practices are very important in control. Without improving cultural practices, you may not achieve long term control.

Use low to moderate amounts of nitrogen, moderate amounts of phosphorous and moderate to high amounts of potash. Avoid applying nitrogen when the disease is active.
Avoid applying N fertilizer before May in Georgia. Early nitrogen applications (March-April) can encourage large patch.
Water timely and deeply (after midnight and before 10 AM). Avoid frequent light irrigation. Allow time during the day for the turf to dry before watering again.
Prune, thin or remove shrub and tree barriers that contribute to shade and poor air circulation. These can contribute to disease.
Reduce thatch if it is more than 1 inch thick.
Increase the height of cut. Reduced mowing heights result in a more dense turf stand, which may create a more favorable environment for large patch development
Improve the soil drainage of the turf.
Control traffic patterns to prevent severe compaction, and core aerate to improve soil drainage and increase air circulation around the shoots and root

For more information on large patch visit https://secure.caes.uga.edu/extension/publications/files/pdf/C%201088_2.PDF

Spring Dead Spot of Bermudagrass

Fall cultural practices and fungicide applications are key for Spring Dead Spot management. The disease is caused by fungi in the genus Ophiosphaerella (O. korrae, O. herpotricha and O. narmari). These fungi infect roots in the fall predisposing the turf to winter kill. As indicated by its name, initial symptoms of spring dead spot are noticeable in the spring, when turf resumes growth from its normal winter dormancy. As the turf ‘greens-up,’ circular patches of turf appear to remain dormant, roots, rhizomes and stolons are sparse and dark-colored (necrotic). No growth is observed within the patches. Recovery from the disease is very slow. The turf in affected patches is often dead; therefore, recovery occurs by spread of stolons inward into the patch. The causal agents of SDS are most active during cool and moist conditions in autumn and spring. Appearance of symptoms is correlated to freezing temperatures and periods of pathogen activity. Additionally, grass mortality can occur quickly after entering dormancy or may increase gradually during the course of the winter. Spring dead spot is typically more damaging on intensively managed turfgrass swards (such as bermudagrass greens) compared to low maintenance areas.

Practices that increase the cold hardiness of bermudagrass generally reduce the incidence of spring dead spot. Severity of the disease is increased by late-season applications of nitrogen during the previous fall.
Management strategies that increase bermudagrass cold tolerance such as applications of potassium in the fall prior to dormancy are thought to aid in the management of the disease. However, researchers have found that fall applications of potassium at high rates actually increased spring dead spot incidence. Therefore, application of excessive amounts of potassium or other nutrients, beyond what is required for optimal bermudagrass growth, is not recommended.
Excessive thatch favors the development of the disease. Therefore, thatch management is important for disease control,
Implement regular dethatching and aerification activities.
There are several fungicide labeled for spring dead spot control.
Timing, selection and application of fungicides are important for preventative management of SDS. Fungicide application in the fall when soil temperatures are between 60° and 80° F provides the best control of SDS
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 (http://www.georgiaturf.com). 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.

For more information on SDS visit https://secure.caes.uga.edu/extension/publications/files/pdf/C%201012_3.PDF

Early detection of bermudagrass leaf spot

Severe leaf and crown rot, caused by Bipolaris ssp. can occur in bermudagrass lawns, sport fields, or golf fairways. Initial symptoms of this disease include brown to tan lesions on leaves. The lesions usually develop in late September or early October. Older leaves are most seriously affected. Under wet, overcast conditions, the fungus will begin to attack leaf sheaths, stolons and roots resulting in a dramatic loss of turf. Shade, poor drainage, reduced air circulation; high nitrogen fertility and low potassium levels favor the disease. To achieve acceptable control of leaf and crown rot, early detection (during the leaf spot stage) is a crucial.

Dollar spot is still active in the fall/early winter

Dollar spot is most prevalent during spring and fall with infections developing rapidly at temperatures between 60 and 75 degrees Fahrenheit combined with long periods of leaf wetness from dew, rain, or irrigation.

Excessive moisture on turfgrass foliage will promote dollar spot epidemics. Irrigating in the late afternoon or evening should be avoided, as this prolongs periods of leaf wetness.
If feasible, prune or remove trees and shrubs to promote air movement and accelerate drying of the turfgrass canopy
A variety of fungicides are available to professional turfgrass managers for dollar spot control including fungicides containing benzimidazoles, demethylation inhibitors
(DMI), carboximides, dicarboximides, dithiocarbamates, nitriles and dinitro-aniline. Several biological fungicides are now labeled for dollar spot control.
For a complete and updated list of fungicides available for dollar spot, visit http://extension.uga.edu/publications/detail.cfm?number=SB28 or http://www.commodities.caes.uga.edu/turfgrass/georgiaturf/Publicat/1640_Recommendations.htm.

Additional information on dollar spot visit https://secure.caes.uga.edu/extension/publications/files/pdf/C%201091_2.PDF

Landscape Alerts and Updates – MAY 2017

June 6, 2017May 26, 2017 by Greg Huber

Slime Mold on Turfgrasses

Has your lawn been slimed? Fear not, the grayish-black sooty substance on your turfgrass is a harmless soil protozoa that has temporarily migrated onto blades and stems to produce and disperse spores. Diagnosis: Slime Mold, Physarum and Fuligo sp./spp. The occurrence is prompted by spells of humid, rainy weather during spring and early summer and is typically short-lived (1-2 weeks). Aside from temporarily hindering photosynthesis, slime molds do not parasitize or damage the turfgrass. Slime mold can be ignored, mowed, raked, or washed off with a pressurized stream of water.

Related Articles: what-is-this-unusual-growth-on-lawns

Lawn Burweed

If you missed the window of opportunity to manage burweed in your lawn in late winter/early spring, then you may be feeling it, literally! The seed burs are now mature and a barefoot stroll across the lawn may inflict you with some painful hitchhikers. At this point, applying a broadleaf herbicide product may kill the weed, but will not eliminate the existing burs that have formed, so mark your calendars for burweed scouting and control next February. If an immediate solution is needed, locate individual plants and physically remove them. Burweed tends to colonize compacted bare areas. For large areas of infestation it may be necessary to scalp and bag the clippings with a mower to remove the burs, followed by turfgrass renovation or establishment on those areas (assuming that you have a warm-season turfgrass species such as bermudagrass, it would not be advisable to scalp a Tall Fescue lawn in May). For more information on scouting for lawn burweed, refer to the previous post “Winter Scouting for Lawn Burweed.”

Turf Aerification

Now is the time to aerify warm-season turfgrasses. Last year, the dry conditions persisting from August through December depleted carbohydrate reserves in warm-season turfgrasses. A delay in turfgrass green-up was common this spring and warm-season turfgrasses are poised to replenish carbohydrate reserves and restore root systems. “If there is a year to seriously consider core aerification, this is it,” says Dr. Clint Waltz, a Cooperative Extension turfgrass specialist with the University of Georgia College of Agricultural and Environmental Sciences. Core aerification relieves compaction, improves air exchange and water infiltration, and stimulates deeper root growth. Hollow-tine aerification is the preferred method, removing soil cores to a depth of 3-4 inches, and having longer-lasting benefits. A light fertilizer application in concert with aerification can be beneficial, but heavy nitrogen applications should be avoided to allow for the replenishment of carbohydrate reserves (over-stimulating top growth depletes carbohydrates reserves).

To make sure soil pH, phosphorus and potassium levels are within recommended ranges for optimum growth, take a soil sample to your local University of Georgia Cooperative Extension office.

Read the full article on Core Aerification and find lawn care calendars for different turfgrass species at www.GeorgiaTurf.com .

Aerification: Restoring Turfgrass Carbohydrate Reserves

February 24, 2017February 17, 2017 by Greg Huber

Dr. Clint Waltz, Extension Turfgrass Specialist with the University of Georgia, reports that hot temperatures and low rainfall in the fall of 2016 likely sent warm-season turfgrasses into winter dormancy with depleted carbohydrate reserves. During “normal” circumstances warm-season turfgrasses accumulate and store carbohydrates from late summer through early fall. Last year, non-irrigated turfgrasses likely suffered drought-induced dormancy and transitioned to winter a weakened condition. With insufficient energy accumulated in root systems, a thin canopy and a two- to four-week delay in the green-up of warm-season grasses might be common this spring.

What can be done to improve the green-up and growth of warm-season turfgrasses this spring?

1) AERIFICATION – Core aerification in late April to mid-May. This will improve air exchange and water infiltration to stimulate root and shoot growth. Performing hollow-tine aerification that removes 1/2 inch diameter soil cores to a 3 or 4 inch depth is the recommended approach.

2) TIMING OF FERTILIZER – Withhold the application of nitrogen fertilizer until soil temperatures at the 4-inch depth are consistently 65 degrees and rising. Visit www.Georgiaturf.com to find lawn calendars that include fertility recommendations for each species. Soil temperature data from the Georgia Automated Environmental Monitoring System can be found at www.Georgiaweather.net.

3) SOIL TESTING – Collect a soil sample and submit for testing to ensure that soil Ph, phosphorous, and potassium levels are within the recommended ranges for optimum growth. Contact your local UGA Extension Agent about submitting a soils sample to the UGA Agriculture and Environmental Services Laboratory or call 1-800-ASK-UGA1.

Restoring carbohydrate reserves this spring is an important step in preparing turfgrasses for a healthy growing season. Read the full article by Dr. Clint Waltz at www.Georgiaturf.com.

Weed Scouting in Mid-Winter

February 10, 2017 by Greg Huber

Weeds can be a major pest of lawns and recreation fields, competing for resources and sunlight while detracting from their natural beauty.

If your spring checklist includes lawn weed management, now is the time to take a closer look at the tiny mat of weed seedlings forming in mid-winter (Jan-Feb.), especially during spells of mild weather and precipitation. The winter-weed inventory is likely to include a mix of early-stage cool-season annual and perennial weeds such as chickweed, henbit, clover, annual bluegrass, burweed, and wild garlic. One advantage of mid-winter weed scouting and management is that many weeds are in the early growth stages and can be effectively controlled by herbicide treatments. In addition, warm-season turfgrasses such as bermudagrass and zoysiagrass are dormant and less susceptible to herbicide injury than during spring green up. Mid-winter is an excellent time to scout for cool-season weed species and get an early jump on management while conditions are favorable.

Below are examples of lawn weeds commonly observed in mid-winter:

Pictured above: Henbit (left), Plantain (center), Tall Fescue in bermuda (right).

POSTEMERGENCE WEED CONTROL

Selective control of broadleaf and grassy weeds in turfgrass can be an effective strategy in mid-winter using the appropriate postemergence herbicide product(s). It should be noted that during the winter months the visible effects of certain herbicides may be masked by cool weather (the weeds may be dead and not know it yet!) Mature perennial weeds such as dandelion, clover, and undesired patches of tall fescue can be effectively spot-treated during mid-winter using selective and non-selective herbicides. It is essential to select products appropriate for the particular species or turfgrass when selecting herbicides. St. Augustinegrass and Centipedegrass are particularly susceptible to certain herbicide injuries, even during the winter months. Combination products containing fertilizer and herbicides may be appropriate for weed control in cool-season turfgrass species such as Tall Fescue during the late winter. However, combination products containing nitrogen fertilizer are NOT recommended for warm-season grasses during the winter months. Applying nitrogen to dormant warm-season grasses in mid-winter does not provide benefits to the turfgrass and promotes the development of diseases such as large patch.

Remember, turfgrass and weed identification is essential to determining the appropriate herbicide product, timing, and application rate. There are no miracle products or “one size fits all” solutions to weed control. Herbicide recommendations are based on many factors including the turfgrass species, weed species, temperature range, and environmental factors. For assistance with turfgrass and weed identification, contact your local UGA Extension Agent at 1-800-ASK-UGA1.

Download the 2017 Turfgrass Pest Control Recommendations for Professionals at www.GeorgiaTurf.com for the latest information on weed management, scheduling, and pesticide information.

References:

McCullough, Patrick E. PhD, Waltz, Clint PhD, (2015). UGA Extension Bulletin (C 978). “Weed Control in Home Lawns.”

Drought Response Level 2: Outdoor Watering Information

November 18, 2016 by Greg Huber

Prolonged dry weather has prompted an elevated drought response for northwest Georgia. Effective November 17, 2016, fifty-two counties have entered a drought response level 2 and fifty-eight counties are exercising a drought response level 1. Rainfall has been scarce since August and water conservation is the banner message. The Georgia Water Stewardship Act of 2010 establishes certain outdoor watering protocols to conserve water during times of drought. These rules apply to all properties served by state permitted water systems.

Highlights of Drought Response Level 1:
A drought response level 1 initiates a public information campaign to explain drought conditions and the need for water stewardship and conservation. Normal outdoor watering should follow best management practices and is allowed between the hours of 4:30pm and 10am any day of the week.

Highlights of Drought Response Level 2:
For existing landscapes, a drought response level 2 initiates the odd/even watering schedule by address for sprinkler systems. For even addresses (ending in zero, 2,4,6,8) watering is allowed as needed on Wednesdays and Saturdays between the hours of 4pm and 10am. For odd addresses (ending in 1,3,5,7,9) watering is allowed as needed on Thursdays and Sundays between the hours of 4pm and 10am. Sprinkler systems should always be properly maintained and adjusted. Evapotranspiration is much lower during the fall and winter and minimal irrigation is needed to prevent winter desiccation using a rate of 1/2 inch precipitation per week or less during periods of dry weather.

New Landscapes:
Under all levels of drought response, a 30 day exemption period is allowed for the establishment of new landscapes. Once the establishment period has expired, drought response watering practices should be followed accordingly.

Other Allowable Exemptions:
Handwatering using a hose with an automatic shut-off nozzle
Food gardens
Hydroseeding
Drip irrigation or soaker hoses
Horticulture crops intended for sale, resale, or installation
Athletic fields, golf courses, and public recreation areas
Maintenance or calibration of an irrigation system
Water from private wells and bodies of water on property (not exceeding state withdrawal limits)
Water from an alternate source (grey water, rain water, air-conditioner condensate)
Commercial Pressure Washing

Summary:
Stay informed on the latest drought information for your area (see helpful resources and information below). While natural precipitation is generally sufficient to prevent plant desiccation in established landscapes during fall and winter, extremely dry conditions may require supplemental watering to help mitigate plant damage. Follow responsible watering practices and properly manage irrigation systems to protect plant health while promoting a culture of water conservation in Georgia. Register for training opportunities such as the upcoming “Irrigation Training for Landscape Professionals” at the EDGE Expo at the Gwinnett Infinite Energy Center on December 8, 2016.

For more information on proper watering practices and training opportunities, contact your local UGA Extension Agent or call 1-800-ASK-UGA1.

Helpful Resources and Information:
http://extension.uga.edu/publications/
www.GeorgiaTurf.com
www.GeorgiaWatersmart.com
https://epd.georgia.gov/water-conservation

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