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Wilted Leaves Not Always a Sign Plants Need Water

Published on 09/19/19

Wilted leaves aren’t always a sign that the plant needs water

By Paul Pugliese for CAES News

As summer slowly melts into fall, temperatures are still reaching the high 90s and many plants wilt in the afternoon sun.

Plants with big leaves, such as hydrangeas and angel trumpets, are often the first to get a little droopy in the hotter part of the day. It’s very tempting to water plants that are wilted at the end of the day, but late afternoon is not the best time of day to determine whether your landscape plants need water.

There are two problems with watering in the afternoon. First, water that remains on the leaves of plants throughout the evening is more likely to invite disease problems. For example, hydrangeas and roses are highly susceptible to leaf spot diseases such as Cercospora, anthracnose or black spot.

Watering in the morning as the sun rises allows leaves to dry more quickly and minimizes these disease problems. It is even better to avoid wetting the leaves at all and just water the roots with a drip irrigation system. If you hand-water your plants, invest in a watering wand with a water breaker nozzle that can be used to apply water directly to the roots. Remember, don’t water the leaves.

The second problem with watering in the afternoon is that people have a tendency to water plants that don’t actually need watering. Although many plants appear wilted in the afternoon, that doesn’t always mean they need water.

Wilting is an adaption that many plants use to reduce water loss during the hottest part of the day. A wilted leaf has less surface area exposed to sunlight and therefore will not lose water as quickly.

Plants that are wilted in the afternoon will often perk back up at night and look perfectly happy by morning. If the plants’ leaves do not appear stressed in the morning, they can probably go another day or two before needing water.

In some situations, plants that are watered every afternoon may get too much water from their well-intentioned caretaker. Georgia red clay soil can hold water for several days after a good soaking rain.  One inch of rain or irrigation will soak clay soil several inches deep. Established landscape plants and mature trees can extract this water and maintain their water needs without needing any additional rain or irrigation for seven to 10 days.

Newly planted trees and shrubs may need supplemental water more often for the first couple of years until their roots grow deep enough to seek out water in the subsoil. Let the plants tell you when they need water.

Even new trees and shrubs can go a couple of days without being watered. When you do water, soak the soil deeply to encourage deeper rooting — this will pay off in the long run as the plant acclimates to its new environment and is able to take care of itself for extended periods of time without rain.

Adding a few inches of mulch around trees and shrubs will conserve soil moisture and help reduce extreme temperatures and drying of surface roots.

Permanent wilt may happen if plants remain wilted even after you water them. There are certain soilborne diseases — such as Fusarium wilt, bacterial wilt, and Phytophthora — that can infect the stems or roots of plants and literally stop the flow of water. This is a common problem in vegetables like tomatoes and certain landscape plants such as rhododendrons. The plants might start out with one or two branches that wilt and then eventually the entire plant wilts. Unfortunately, there are no effective treatment options for plants infected with one of these permanent wilt diseases.

Ironically, infected plants often wilt more dramatically in the early stages of the disease, especially in the afternoon. This causes people to water them more often. Excessive watering actually helps these diseases spread. To remove the fungal disease, dead or dying plants, along with the soil around the roots, should be completely removed. The spores of these diseases can survive in the soil for many years and infect the next plants you try to grow there.

Sometimes, these diseases hitchhike on infected plants bought from nurseries. It’s always a good idea to inspect the roots before you buy a plant.

Gently slip the plant out of the nursery pot and examine the roots all the way to the bottom. A healthy plant will have white, healthy roots throughout the soil. An unhealthy plant will often have black or brown roots on the lower third of the root ball. This could indicate the plant was overwatered at the nursery or may already be infected with a root disease.

For more information on growing healthy plants and other agriculture topics, see the University of Georgia Cooperative Extension publications at

Paul Pugliese is the agriculture & natural resources agent for the University of Georgia Extension office in Bartow County.

Hurricane Dorian

Published on 08/29/19

Prepare now for Hurricane Dorian’s arrival, UGA climatologist says

By Pam Knox, Sharon Dowdy for CAES News

Hurricane Dorian may bring power outages, downed trees, heavy rain and possibly brief tornadoes to Georgia this weekend and well into next week, according to Pam Knox, director of the University of Georgia Weather Network and an agricultural climatologist.

“Dorian’s path has been farther east than originally forecast, which means that its circulation has avoided the mountainous terrain of the Dominican Republic and Puerto Rico. That means it was less disrupted than expected, and now is forecast to approach the east coast of Florida as a potentially major hurricane by Monday,” Knox said.

The storm is expected to affect all of the Georgia coast, but Dorian’s path is likely to change significantly over the coming days, Knox said.

“The more eastward path has also added time before the projected landfall, so that gives us a little extra time to prepare. There is also a slight chance the storm will recurve to the northeast before it hits the coast — in that case, breathe a sigh of relief and think of this as preparation for the next storm,” she said.

Southeastern Georgians should be prepared for tropical storm-force winds to hit as early as Sunday morning. As in any event with potentially heavy flooding, Knox urges Georgians to move equipment and livestock out of low-lying areas before the storm arrives and stock up on fuel and the capacity to provide power for milking, drying of crops, etc. Any outdoor items that could be dislodged by heavy winds and become a projectile should be secured.

Knox says the weather should remain dry through Saturday, but after that the chances for rain go up.

“Along the coast, onshore flow coupled with the already higher-than-normal tides will increase the chances of flooding, and that will only be made worse by the tropical rainfall,” she said. “Spiral bands ahead of the storm could produce brief tornadoes in isolated thunderstorm cells. Power outages are likely due to the combination of wet soil and strong winds blowing trees over.”

With the one-year anniversary of Hurricane Michael just over a month away, Knox urges southwestern Georgia to not let their guard down.

“A number of computer models indicate that the storm could cross the Florida peninsula and enter the Gulf of Mexico, where sea surface temperatures are above normal. A recurve to the north into Georgia is a possibility and, even if the storm weakens as you might expect, heavy rain and brief tornadoes could occur in that situation,” she said.

If Dorian crosses Florida, the storm’s timing would move to early next week, she said.

Georgians in central and northern Georgia have more time to watch the storm develop. Knox says this valuable time should be used to prepare for potential tropical storm-force winds and heavy rain likely Tuesday through Thursday.

“That could change depending on where Dorian actually goes and how fast it is moving,” she said. “The Labor Day holiday weekend means that there will be extra people on the road and in hotels, so don’t wait until the last minute to get gasoline, cash and whatever else you might need in case of power outages and road closures.”

Knox recommends Georgians get current information from reliable sources like the National Hurricane Center, National Weather Service and local emergency managers. Stock an emergency radio with fresh batteries to stay informed should a power outage occur in your area.

For the latest information from UGA agricultural climatologist Pam Knox, follow her on Twitter at @SE_AgClimate, on Facebook at SEAgClimate and on her blog at

For more storm preparation resources from UGA Extension,

Pam Knox serves as University of Georgia Agricultural Climatologist with UGA Department of Crop and Soil Science.
Sharon Dowdy is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.

Monarch butterflies migrating through Georgia

Published on 10/23/19

Monarch butterflies migrating through Georgia now

By Becky Griffin for CAES News

The time of the year has come when Georgians look to the sky to watch for signs of Monarch butterfly migration.

These butterflies are on their way to the Sierra Madre of Mexico to overwinter on the oyamel (or sacred fir) trees of the area. The fir trees provide the perfect habitat, combined with the area’s optimal temperatures and humidity, to ensure that the butterflies survive the winter.

Reports around Georgia are that Monarch populations are high. A poll taken of insect enthusiasts showed that 83% have seen Monarchs heading south this year. Thirty percent of respondents indicated that they are seeing a higher number of Monarchs than last year.

This is terrific news, as Monarch population numbers have been inconsistent over the last several seasons.

To increase the chances of seeing this phenomenon and to assist the butterflies, plant a fall migration garden. Monarchs descend from their high migration path looking for food resources.

Research shows that migrating butterflies respond to tall flowers that are easily accessible. Joe Pye weed (Eutrochium purpureum), goldenrod (Solidago spp.) and Mexican sunflower (Tithonia rotundifolia) are all proven Monarch attractors.

Several fall-blooming native aster plants (Aster spp.) are perfect for these butterflies as well.  The butterflies do not need milkweed (Ascelpias spp.), their larval host plant, at this time of the year, but be sure to include milkweed in your summer butterfly garden.

To follow the Monarch migration and to report your butterfly sightings, visit Journey North at This organization has tabulated the reports of citizen-scientists for many years and is a great resource for school groups.

Monarch Watch, accessible at, provides online information about these insects and their habitat needs.

It is amazing to realize that this super generation of migrating butterflies endure the hazards of the trip to go to a place that they have never been before. If you miss the fall Monarch migration, spend time getting your garden ready for the Monarchs’ return in the spring. Contact your local University of Georgia Cooperative Extension office for more information about butterfly gardening and habitat building.

Becky Griffin is an educational program specialist with the University of Georgia Extension in Cobb County.

Lego Forage Specialist

Published on 09/19/19

‘Lego Forage Specialist’ helping spread forage news across Georgia

By Clint Thompson for CAES News

University of Georgia Cooperative Extension Forage Agronomist Lisa Baxter is using her social media savvy and love for Legos to share timely information with Georgia farmers.

When Baxter joined the UGA Tifton campus in March, she set out to find a way to reach as many people as possible with information in her field.

Inspired by a Facebook advertisement for custom Legos, Baxter customized her own Lego minifigure to create the “Lego Forage Specialist” or “Lego Lisa.” Several times a week, Baxter photographs her “mini-me” at work in the field or in the office. Then she adds captions to the photos, including useful tidbits of information for audiences on Instagram, Facebook and Twitter.

To date, Lego Lisa has about 250 followers on social media where she tells jokes, advises Georgia producers about upcoming state meetings, and cautions growers about problems that could affect their crops.

“It’s a different way of getting a message across than just listening to a 30-minute PowerPoint presentation or reading another email,” Baxter said. “If we see armyworms that have been reported, we’ll do a picture with a sweep net saying, ‘You need to scout for armyworms.’ We had some herbicide damage in some Bermuda grass plots, so we took a picture of that and said, ‘If you’re pursuing summer weed control options, be aware of potential stunting.’”

Using her affinity for Legos, Baxter customizes the minifigure’s attire and accessories based on the message.

When she’s working outside, the weather conditions generally determine how Lego Lisa is dressed. In most photos, Baxter holds the figure’s feet and keeps her hand out of the picture and to keep the little Lego from blowing away in strong winds.

For National Forage Week in June, Baxter ordered several costumes, including a lab coat, for her Lego sidekick. Her clients have joined in on the fun and one UGA Extension county agent brought in a few of her child’s Lego accessories for Lego Lisa because the child was worried she didn’t have any toys to play with.

Many industry representatives even request the Lego’s presence for events and their own social media efforts. Even though she is tiny, Lego Lisa is bridging the gap between industry and Extension.

Baxter feels that having Lego Lisa appear on her social media pages rather than her own image is a novel way to bring attention to the information she shares.

“We have a lot of new Extension agents. When I was at winter conference, they asked how many agents have five years or fewer experience and about half the room shot their hand up. (I created) Lego Lisa to reach that clientele. They’ll see things scrolling through their phone and she does provide a chuckle,” Baxter said.

David Allen, communications coordinator for the UGA CAES Office of Communications and Creative Services, believes Baxter’s creativity will serve her and UGA Extension well in relaying messages via social media.

“We love to see faculty embracing social media and finding creative ways to connect with constituents through the web. It will be fun to see the Lego Forage Specialist build its following and see the engagement generated across multiple platforms,” Allen said.

To see where Lego Lisa has been lately, follow her at, or

Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.

Blue-Green Algae in Ponds

Published on 08/15/19

UGA Extension urges Georgians to keep animals away from ponds that may contain toxin-producing algae

By Sharon Dowdy, Merritt Melancon for CAES News

The sudden and unexpected death of a Marietta, Georgia, couple’s beloved dog after swimming with its owners in Lake Allatoona has filled social media feeds since the incident on Aug. 10. The incident brings to light the dangers of toxic algae growth. In neighboring North Carolina, another couple lost three dogs in one day after an afternoon swim in a pond.

The cause has been identified as the blue-green algae species Microcystis aeruginosa, a cyanobacteria that produces a potent liver toxin.

Algae often grows in ponds and lakes during abnormally dry conditions such as those Georgia is currently experiencing. Toxin-producing algae can be lethal to livestock who use farm ponds as their water source, but common toxins like microcystins can also impact larger bodies of water, said Gary Burtle, University of Georgia water quality and fisheries expert.

While Georgia isn’t officially in a drought, areas of the state have been hotter and drier than normal, Burtle said.

Conditions like these can cause more algae to grow and bloom in bodies of water as a result of the increased nutrient load in ponds and lakes, he said. In ponds used to water cattle and horses, this might lead to problems with toxic algae and unsightly water.

Color changes in a pond can be a clue that algae are blooming. Blooms of algae and cyanobacteria often look like green, blue-green or reddish-brown paint floating on the surface of small bodies of water, usually near the shoreline. This scum formed by algae is an indicator that the pond may be unsafe, Burtle said.

“Humans should not swim in this water and animals should not be allowed access to it until the bloom returns to normal by dilution from rainfall or treatment with algaecide,” said Burtle, who has fielded numerous calls from UGA Cooperative Extension agents this week as questions have poured in from the public. “You know a pond is headed for trouble when the algae bloom is so thick that visibility is less than 12 inches into the water column.”

In 2012, Georgia experienced serious drought conditions and some Gwinnett County cattle died as a result of a cyanobacteria bloom. Animals affected often appear weak, exhibit muscle tremors and convulsions, and have bloody diarrhea.

Farm animals should be kept away from the water source and provided with an alternative source of clean water until the pond has been tested and is declared free of toxins, Burtle said.

“If you have a fear about the water, move your animals to a safe water source,” Burtle said. “Install a water tank and fill it up every day or so. And use common sense. If there’s a scum on the pond and you think there might be a problem, exclude your animals and have the water tested.”

UGA Extension agents can help Georgians test their pond or lake water for the presence of toxins from algae blooms through UGA College of Agricultural and Environmental Sciences laboratories.

Cyanobacteria blooms in ponds and lakes are difficult to control, Burtle said. Using chemicals releases more toxins into the pond, rendering it useless as a water source for weeks or months. High daytime temperatures can also force the cyanobacteria blooms to the bottom of the pond, where toxins are released.

Harmful algal blooms need nutrients, sunlight, and warm, stagnant water to develop.

To help prevent blooms, UGA Extension urges pond owners to leave vegetated buffers around ponds, to limit livestock access and to avoid over-fertilizing surrounding areas. Pond owners who would like to learn more about controlling algae should read UGA Extension Bulletin 1445, “Managing Algal Blooms and the Potential for Algal Toxins in Pond Water.”

Sharon Dowdy is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.
Merritt Melancon is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.

Control of Cowpeas

Cowpea Control (Prostko)

Every so often, I get a few inquiries about herbicides for the control of cowpea (Vigna unguiculata) (Figure 1). Unfortunately, cowpea (also known southern pea, black-eye pea, or crowder pea) can be a very difficult plant to control and not much research data is out there.  In preparing our UGA Weed Science graduate students for the upcoming 2019 National Weed Science Contest, I was able to collect some good data for various herbicides (Table 1).

In summary, the following herbicides could be used for the control of cowpea depending upon the planted crop:  PRE = Atrazine, Balance Flex (isoxaflutole), and Tricor (metribuzin); POST = Classic (chlorimuron), Engenia (dicamba), Enlist One (2,4-D), Envoke (trifloxysulfruon), Gramoxone (paraquat), Liberty (glufosinate), Osprey (mesosulfuron), Roundup (glyphosate), Sharpen (saflufenacil), and Stinger (clopyralid).

Figure 1.  Cowpea

Table 1.  Cowpea (‘Top Pick Pinkeye Purple’) control with PRE and POST herbicides, TyTy, Georgia, 2019.1

Herbicide Rate/A


Application Method


Test 1

Control (%)

Test 2

Control (%)

15 DAT3


20 DAT


14 DAT


Harness 7EC 22 PRE 0 0 0
Atrazine 4L 64 PRE 100 100 100
Diuron 4L 26 PRE 0 0 0
Valor SX 51WG 3 PRE 0 10 20
Pursuit 2SL 4 PRE 0 8 0
Balance Flexx 2SC 6 PRE 100 100 100
Callisto 4SC 3 PRE 60 65 0
Prowl H20 3.8ASC 48 PRE 0 5 0
Zidua 85WG 1 PRE 0 10 0
Dual Magnum 7.62EC 21 PRE 0 12 0
Spartan 4L 1 PRE 0 0 0
Tricor 4L 24 PRE 100 100 100
Enlist One 3.8SL 13 POST 95 95 100
Buctril 4EC 12 POST 50 70 30
Classic 25DG + COC4 0.5 POST 95 95 85
Select Max 0.97SC + NIS 25 POST 0 10 0
Stinger 3SL 8 POST 95 100 80
Engenia 5SL 6.4 POST 95 95 85
Fusilade DX 2EC + COC 12 POST 0 10 0
Resource 0.86EC + COC 4 POST 0 0 0
Reflex 2SL + NIS 12 POST 50 50 50
Liberty 2.34SL +

N-Pak AMS (2% v/v)

22 POST 100 93 85
Sandea 75DG + NIS 0.66 POST 40 25 30
Osprey 4.5DG + MSO 4.6 POST 70 88 85
Accent 75DG + COC 0.66 POST 65 75 60
Gramoxone 2SL + NIS 32 POST 100 95 90
Facet 75DG + MSO 16 POST 50 60 55
Sharpen 2.85SC + MSO 2.5 POST 95 92 80
Laudis 3.5SC + MSO 3.5 POST 65 68 60
Envoke 75DG + NIS 0.09 POST 85 88 90
Roundup PowerMax 5.5SL 22 POST 100 97 90

1Test 1: Planting Date = May 28; PRE = May 29; POST = June 13 (~8” tall cowpea).

2Test 2: Planting Date = June 17; PRE = June 18; POST = July 8 (~8” tall cowpea).

3DAT = days after POST treatment.

4COC = Agridex @ 1% v/v; NIS = Induce @ 0.25% v/v; MSO = MES 100 @ 1% v/v.

Slippery Algae in Turfgrass

Published on 06/13/19

Rain, overwatering can cause slippery algae to pop up in turfgrass lawns

By Clint Waltz for CAES News

Recent dry weather encouraged the use, and possible overuse, of irrigation systems. Followed by tropical conditions characterized by heavy rainfall and humidity, there have been reports of a jelly-like substance growing in turf.

The jelly-like matter is Nostoc, a genus of cyanobacterium formerly classified as blue-green algae. The algae — commonly known as star jelly and witch’s butter, among other names — may appear suddenly in lawns and other turf areas in warm temperatures following a period of rain, and the algae can also be an indication of overwatering.

In turf, Nostoc generally emerges on a site where the grass is growing poorly due to severe compaction, overwatering or both. It does not cause the turf to decline or die, but it does colonize 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 dries out when moisture 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 because it’s slippery — so be careful walking on it.

However, when it dries out, it can restrict turfgrass growth. Nostoc dries into a black crust that can prevent stolons from rooting, or “tacking,” into the soil. This delays the growth and spread of turfgrass.

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 often or too much). The turfgrass species grown in Georgia perform better when grown on the slightly dry side, so scaling back irrigation and adjusting the irrigation schedule will benefit the grass and can discourage algae.

The second step is to improve the internal soil and surface drainage. Core aeration opens the soil, allows oxygen into the root system and reduces compaction.

Allow the soil surface to dry out, then break up the Nostoc “crust” by cutting the upper ¼- to ½-inch. Breaking the algae into pieces will encourage it to spread. This 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 about turfgrass in Georgia, go to

Clint Waltz is a Cooperative Extension turf specialist with the University of Georgia College of Agricultural and Environmental Sciences.

App Helps Fruit Growers

Published on 06/18/19

App helps fruit growers in Eastern U.S. diagnose disease and insect problems

By Denise M Hatcher for CAES News

Walking through his peach orchard, a farmer notices something he has not seen before on the leaves of a few trees. He quickly pulls out his cell phone and accesses the MyIPM smartphone app.

Through a series of descriptions, audio and images, the free mobile app and tool can help users diagnose crop diseases, insect pests and disorders of fruit crops grown in the Eastern U.S., including apple, blackberry, blueberry, bunch grape, cherry, cranberry, peach, pear and strawberry.

The app was first developed by plant pathologists at Clemson University to give growers a “one-stop shop” to access all of the resources they might need for disease management, says Brett Blaauw, an assistant professor and peach specialist with the University of Georgia Department of Entomology. A couple of years later, two more apps were created: one focused on insect pests and another geared specifically for the Northeastern region of the U.S.

“When I came to UGA, I worked on merging the three separate apps into one master app, which included new tools, crops and functionality,” Blaauw said. “The single MyIPM app currently has nine crops with disease diagnostic tools and six crops for insect diagnostic tools.”

To date, the app has been downloaded more than 2,100 times. Designed to promote integrated pest management in commercial fruit crop production, one of Blaauw’s favorite aspects of the app is that it’s full of useful information for users of both Apple iOS and Android mobile operating systems.

“Not only is there a large list of chemistries that are labeled for each disease or insect pest, but users also have the ability to view high-resolution pictures to identify symptoms and signs of disease and insect injury,” he said. “With that said, my real favorite aspect is that the app is free.”

The app is continually being updated by leading Extension specialists at seven land-grant universities and the Southern IPM Center.

Feedback from users has been overwhelmingly positive. Of the users surveyed, 65% say that the app has helped them manage pests and 70% say that it has increased their knowledge of pests and IPM, according to Blaauw.

“Nearly everyone I talk to about the app is pleased with its functionality and ease of use,” he said.

The app has been downloaded to more than 70 different countries, including India, Mexico and Canada.

Blaauw is currently working on adding a section on beneficial insects to help growers identify “good bugs” using the app. He hopes to see the app expanded to include more crops.

For more information on the MyIPM app, visit

Michele Hatcher is the editor of the Hexapod Herald, the newsletter of the University of Georgia Department of Entomology.

Turf Grass News

Turfgrass Blog: 2019 Edition

Clint Waltz, Ph.D.

University of Georgia Turfgrass Specialist

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 Nostoc “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.



Summer Heat

Published on 05/23/19

Spring season brings summer heat to Georgia

By Clint Thompson for CAES News

Georgia temperatures are rising, and the weather is only going to get hotter with little rain in the forecast. That’s not good news for Georgia’s cotton producers who are in the middle of planting this year’s crop, says Jared Whitaker, University of Georgia Cooperative Extension cotton agronomist.

According to the UGA Weather Network at, temperatures eclipsed 90 degrees Fahrenheit in most of south Georgia this past weekend and are expected to reach 100 F by the middle of next week.

“Cotton is going to be the most sensitive crop to these types of conditions just because of the relatively poor vigor of cotton seedlings compared to other crops Georgia producers plant,” Whitaker said. “Cotton seed is very small and conditions need to be near perfect for several days after planting to ensure we get a suitable stand. When soils dry and temperatures rise, it becomes increasingly difficult for producers, especially in nonirrigated fields.”

Whitaker says that an informal survey he conducted last week revealed that around 50% of the state’s farmable fields had been planted. Progress was a little further along than usual because of good planting conditions in late April. Also, producers are trying to minimize their risk from losses that could occur at harvest by planting some cotton earlier than usual.

He is concerned that poor conditions could delay planting to the point that yields are affected.

“We really need to have a good stand established before the end of the first week of June to ensure that we have enough time to make an entire crop,” Whitaker said. Growers need rainfall within the next couple of weeks to get this crop started in the right direction.

“We’re always a week away from a drought,” Whitaker said. “And that’s certainly the case this year.”

The last substantial rainfall was recorded during the weekend of May 10 through May 12. Three days of rain yielded 1.5 inches in Tifton, Georgia; 0.81 inches in Alma, Georgia; 1.2 inches in Griffin, Georgia; and 1.52 inches in Vienna, Georgia.

But since much of the state’s crops are grown in south Georgia’s sandy soils, any moisture that region receives is soaked up quickly.

UGA Extension peanut agronomist Scott Monfort says that approximately 65% of Georgia’s peanut crop has been planted. But like the state’s cotton farmers, Georgia’s peanut producers will need to monitor their crop’swater needs during this extremely hot and dry period.

“To have high temperatures this early is pretty tough. It means these plants are going to go through heat stress earlier than normal this year and farmers are going to have stay on top of it as far as irrigating,” Monfort said. “While we normally wouldn’t irrigate this early, we might have to start if we lose too much moisture.”

Growers also need to be careful planting in fields with marginal moisture.

Summer doesn’t officially begin until June 21. Pam Knox, UGA Extension agricultural climatologist, believes that temperatures in June, July and August will depend largely on how much rainfall Georgia gets.

“There is not much correlation between early season heat waves and the rest of the summer. However, if it stays dry, then hotter-than-normal conditions are likelier just because all of the sun’s heat goes to warming the air instead of evaporating water from the soil and plants,” she said.

For more information about what weather to expect this summer, read Knox’s climate outlook on her blog at

Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.

Some Georgia Lawns “Greening Up” Faster Than Others

While many warm-season turfgrass species have shown signs of significant green-up, some grasses and locations still have an appearance of being dormant or slowly transitioning.

To date, the average 4-inch soil temperature for the entire month of April on the University of Georgia campus in Griffin, Georgia — fairly central for the state — is 64.1 degrees Fahrenheit. In general, this is warm enough to get green growth, but it is barely warm enough to stimulate root growth or initiate new growth from rhizomes buried within the upper couple inches of the soil for Bermuda grass and zoysia grass.

Understanding the growth characteristics of Georgia’s warm-season species and considering recent environmental factors, it is not surprising that most grasses appear green while others seem slow to green up. The “slower” grasses, or locations within the landscape, could be delayed by other influences.

If grass is growing in an area on the north side of a building, in a low area that retains more water, in a wet spot in the landscape, where the ground is shaded or geographically north of Griffin, it may be a little slower to green up. Water is a good buffer of heat, meaning that it takes more of the sun’s energy to warm the soil to the same temperature than if the soil were dry. Wet areas will green up more slowly than drier areas.

Considering the amount of rain the state has received since last summer, all Georgia soils likely have good to excellent moisture content. Also, a thin area may be slower to cover, or appear green, because the soil temperatures for initiating new shoots from rhizomes will take more time. It takes more time for warmth to move through the soil and trigger new growth than it takes for the new shoot to reach the soil surface.

Warm-season grasses have changed substantially over the past two to three weeks. Likewise, the next two to three weeks should encourage growth and green-up.

They say “patience is a virtue,” and a little green grass seems to cause us to be less virtuous. Be patient and stay with the program. Georgia’s warm-season turfgrass species should be growing strong shortly.

For more turfgrass information from UGA Cooperative Extension, go to

Clint Waltz is a Cooperative Extension turf specialist with the University of Georgia College of Agricultural and Environmental Sciences.