Dark, rust-colored dieback symptoms of Botryosphaeria (Bot) canker. G. Moody
This disease is Bot canker. Bright, rust-colored branches and yellowing or browning of shoots or branches are the first observed symptoms. Closer inspection reveals the presence of sunken, girdling cankers at the base of the dead shoot or branch. Sometimes, the main trunk shows cankers that might extend for a foot or more in length. These cankers rarely girdle the trunk, but they will kill branches that may be encompassed by the canker as it grows. Read more info in the following publication including disease management.
Authors – Alfredo Martinez, UGA Plant Pathologist, Jean Williams-Woodward, UGA Plant Pathologist and Mila Pearce, Former UGA IPM Homeowner Specialist
Leyland cypress has become one of the most widely used plants in commercial and residential landscapes across Georgia as a formal hedge, screen, buffer strip, or wind barrier. The tree is best suited for fertile, well-drained soils. However, when young, the tree will grow up to 3-4 feet per year, even in poor soils. The tree will ultimately attain a majestic height of up to 40 feet.
Leyland cypress is considered relatively pest-free. However, because of its relatively shallow root system, and because they are often planted too close together and in poorly drained soils, Leyland cypress is prone to root rot and several damaging canker diseases, especially during periods of prolonged drought. Disease management is, therefore, a consideration for Leyland cypress.
This UGA Publication discusses several Leyland Cypress diseases and their management.
Postemergence herbicides may be applied to suppress bermudagrass populations and reduce competition with desirable turfgrasses. Repeat applications of selective herbicides are needed for best results but may be injurious to the desirable species. Furthermore, tolerance to herbicides may vary by turfgrass cultivar and end-users should consult with local Extension specialists for application rates and recommendations.
Bermudagrass Control in Centipedegrass
Centipedegrass is a popular low-maintenance lawn species in Georgia. Centipedegrass generally has slower growth than bermudagrass with less potential for competition during the summer. Clethodim (Envoy, others) and sethoxydim (Segment, others) are cyclohexenadione herbicides that inhibit lipid synthesis in grassy weeds. Sensitive species exhibit leaf injury with reddish discoloration before significant necrosis.
Bermudagrass is sensitive to both clethodim and sethoxydim and repeat applications may suppress populations in centipedegrass. Turf managers should schedule applications approximately every three weeks during active growth. For best results, add a nonionic surfactant at 0.25% v/v with clethodim to enhance spray retention and apply no sooner than three weeks after spring green up. Certain sethoxydim products (e.g., Segment) may have a built-in adjuvant already mixed in the formulation and the addition of a surfactant is not required. For both herbicides, turf managers should avoid mowing one week before or after treatment.
Bermudagrass Control in St. Augustinegrass
St. Augustinegrass is a major warm-season turfgrass used for lawns in southern Georgia. St. Augustinegrass has desirable heat and drought tolerance but is sensitive to many herbicides. Selective herbicides for controlling grassy weeds, such as crabgrass and goosegrass, are limited in St. Augustinegrass lawns. Bermudagrass infestations are also difficult to manage.
St. Augustinegrass has good tolerance to ethofumesate (PoaConstrictor, Prograss), which may be used in combination with atrazine to control bermudagrass. Ethofumesate is an unclassified herbicide that has postemergence activity for grassy and broadleaf weed control in nonresidential St. Augustinegrass and cool-season grasses. Ethofumesate has several toxic effects in susceptible species, such as bermudagrass, but arrested cell division appears to be the primary mechanism of selectivity.
Atrazine inhibits photosynthesis in susceptible weeds and is in the triazine herbicide family. Triazines interfere with electron transport during photosynthesis and eventually lead to cell membrane destruction and cellular leakage. Susceptible weeds initially exhibit chlorosis on leaf margins. Actively growing bermudagrass is sensitive to atrazine applications and its addition to ethofumesate treatments provides postemergence and some residual control of bermudagrass. Atrazine alone may provide some bermudagrass suppression but does not provide long-term control.
Applications of ethofumesate with atrazine should be initiated during bermudagrass spring green up. Herbicide regimens that begin on actively growing bermudagrass in summer will likely be ineffective. St. Augustinegrass often responds to applications with stunted growth and discoloration. Repeat applications should be made after 30 days or once turf has recovered from any potential injury. See the current edition of the Georgia Pest Management Handbook for rates and further information about bermudagrass control.
Bermudagrass Control in Tall Fescue and Zoysiagrass
Fenoxaprop and fluazifop are used for postemergence grassy weed control in tall fescue and zoysiagrass. Sensitive weeds exhibit injured leaf tissue with reddish discoloration while plant nodes become necrotic and die. Theses herbicides have no activity on broadleaf weeds but provide excellent grassy weed control.
Fenoxaprop (Acclaim Extra) and fluazifop (Fusilade) may be used alone in tall fescue and zoysiagrass lawns. Fenoxaprop may also be used in residential and nonresidential Kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.) and other cool-season turfgrasses. Fluazifop may be used in commercial and nonresidential turf. Generally, tall fescue has good tolerance to these herbicides. There is greater potential for injury on zoysiagrass than on tall fescue from fenoxaprop or fluazifop treatments, especially fine-textured varieties.
Triclopyr (Turflon Ester, Turflon Ester Ultra) at high rates (0.75 to 1 lb ai/acre) is injurious to bermudagrass. Tank mixtures with fluazifop or fenoxaprop have been shown to reduce tall fescue and zoysiagrass injury without compromising control. The addition of an adjuvant to tank mixtures of fluazifop with new triclopyr formulations (e.g., Turflon Ester Ultra) is unnecessary and may increase turf injury.
In Georgia, initial applications of fenoxaprop or fluazifop should be scheduled around June 1 and repeated every 20 to 30 days. Fluazifop alone should be applied with a non-ionic surfactant at 0.25% v/v of spray solution. Acclaim Extra (fenoxaprop) does not require the addition of an adjuvant. See the current edition of the Georgia Pest Management Handbook for rates and application comments for fluazifop and fenoxaprop treatments for bermudagrass control in tall fescue.
Nonselective Bermudagrass Control
Spot treatments of nonselective herbicides are the most effective method for controlling bermudagrass. Glyphosate is a nonselective herbicide that is widely used for spot treatments of perennial weeds in turfgrasses. Glyphosate is a foliar-absorbed herbicide that is systemically translocated with no preemergence activity for weed control.
Spot treatments of glyphosate should be made to bermudagrass patches and surrounding areas to control any runners that may be intermingled with desirable turfgrasses. Broadcast applications can effectively renovate or kill existing vegetation but high rates and multiple applications are required to control bermudagrass. Glyphosate should be applied to actively growing bermudagrass. Repeat treatments will be required for complete control. Cultural practices that disrupt plant growth, such as vertical mowing and aerification, should be delayed for seven days after treatment.
Glyphosate requires optimum translocation in order to control bermudagrass rhizomes and plants emerging from lateral stems. Perennial grasses generally have greater translocation of photosynthate from leaves to stems in fall than spring, which increases glyphosate movement to rhizomes. Fall glyphosate applications generally control bermudagrass more effectively than summer treatments. Numerous glyphosate products are available under a wide variety of trade names.
Big cities with large expanses of concrete, asphalt, and buildings are usually warmer than the suburbs or countrysides that surround them, a phenomenon known as the urban heat island effect. Now new research from North Carolina State University shows that these urban heat islands increase the number of young produced by the gloomy scale insect — a significant tree pest — by 300 percent, which in turn leads to 200 times more adult gloomy scales on urban trees.
Paul Pugliese, Agriculture & natural resources agent for the University of Georgia Cooperative Extension office in Bartow County
Japanese beetles dine on canna lily branches Image credit – Sharon Dowdy.
With their metallic copper and blue-green bodies and bronze wings, Japanese beetles might be considered beautiful if not for the damage they cause. The plentiful beetles munch holes into the leaves of landscape plants leaving what is often described as skeletal remains.
Prior to last year, Georgia had a few years of drought and unusually mild winters. The warm, dry soil conditions were not conducive for Japanese beetle grubs to survive over the fall and winter throughout most of Georgia. This gave Georgia gardeners and landscapes a nice reprieve from the pest and its damage.
Perfect conditions return
This past winter was ideal for Japanese beetle grubs and home and commercial gardeners are suffering through a resurgence of adult beetles this summer. The severity of local Japanese beetle populations varies depending on temperature and soil moisture. Most surveys indicate that Japanese beetles do not occur further south than the “fall line” between Macon and Augusta in Georgia. Yet, they can be found as far north as Canada.
If you’ve fought Japanese Beetles before, there’s a good chance they will return to your landscape – especially if your have some of their preferred plants. Japanese beetles feed on more than 300 species of broad-leaved plants but prefer about 50 species. Commonly attacked hosts include peach, cultivated and wild grapes, raspberry, plum, roses, apple, cherry, corn, hibiscus, hollyhock, dahlia, zinnia, elm, horse chestnut, linden, willow, crape myrtle, elder, evening primrose and sassafras.
They love leaves
The good news is the beetles only affect the leaves of trees and shrubs, so healthy plants can tolerate significant leaf loss without long-term consequences.
Adult Japanese beetles live four to six weeks, lay eggs (mostly in mid-August) and die. If the soil is sufficiently moist, the eggs will swell and produce larvae in about two weeks. The rest of the year, the beetles live underground in a larval stage feeding on the roots of grass and other plants before maturing into adult beetles in the summer.
Japanese beetle larvae are plump, C-shaped white grubs often seen in the spring when garden soil is first tilled. The grubs need soil moisture to survive the winter. Frequently irrigated lawns and landscapes tend to have higher grub populations.
Adult beetles emerge from the soil and begin seeking out plants for food in late May and early June. The first round of beetles are known as “scouts” because they find a good food source and release pheromone scents to attract more beetles. The masses then gather to feed and mate.
Control the first ones!
The key is to catch the early arrivers as soon as possible. Handpick or knock adult beetles off plants and drown them in soapy water. This is an effective control option for managing small infestations and preventing them from attracting more beetles.
Pheromone lure traps are not recommended for general Japanese beetle control in a small garden. They tend to attract more beetles to the area than would normally be present. Trapping should be done in areas away from gardens or landscapes to lure beetles away from desired plants.
Adult beetles can be controlled with over-the-counter insecticides. During heavy beetle outbreaks, sprays may be needed every seven to ten days to protect high-value, specimen plants like roses. A single application of a longer-lasting systemic insecticide, like imidacloprid, needs to be made 20 days before adult Japanese beetles are expected — usually around mid-May. Most systemic treatment options are not labeled for use on plants that produce edible fruits. Read and follow pesticide label’s application rates and safety precautions.
Controlling the grub stage generally has little effect on the overall damage caused by adult beetles, since adults can fly into your landscape from up to a mile away. Most homeowners rarely have grub populations large enough to cause damage to home lawns. Treatment may be necessary if more than five to ten grubs per square foot are present in lawns. Late summer and early fall insecticide applications are most effective at killing young grubs.
Cicada killer – Jessica Lawrence, NC State Entomology Department, Bugwood.org
The cicada killer wasp is the largest wasp in Georgia. The cicada killer wasp is almost two inches long. Although intimidating in appearance, these wasps are not something we humans have to worry about. Cicadas, on the other hand, should be very afraid. Cicada killer wasp adults feed on nectar but use paralyzed cicadas to feed their young.
Female cicada killers are hard to provoke to sting. The female uses her stinger to paralyze her prey (cicadas) rather than in self defense. The female’s attention is focused on providing food for her babies, so she poses little threat to humans.
Cicada killers prefer to nest in sandy open sunlit areas. As the female digs, she kicks out soil that forms a semicircle around the burrow opening. She burrows six to ten inches into the ground, prepares a chamber, catches a cicada to fill the chamber, lays an egg on the cicada, and seals the chamber. She may do this over a dozen times in one burrow.
Cicada killer – Ronald F. Billings, Texas Forest Service, Bugwood.org
When a female finds a cicada, she paralyzes it with her stinger, straddles it, and attempts to fly with it to her burrow. Because the cicada typically weighs more than she does, these flights are usually hops, with more dragging than gliding.
The egg hatches in a few days and the larva feeds on the paralyzed cicada until nothing is left but a shell. Then the wasp larva pupates within the burrow, remaining there until the next spring.
Males cannot sting; their only defense is intimidation. They patrol the nesting area, trying to divert attention away from the female, allowing her to provision her nest with cicadas. Meanwhile the male is using threatening tactics to distract potential predators. He may even dive bomb perceived threats. Since the males do not have stingers, they are completely harmless. They must rely on bluff, bluster, and bravado to protect their families.
Because cicada egg laying can be damaging to trees and shrubs, cicada killer wasps are very beneficial, providing free biological control. However, homeowners who do not want these wasps around can modify their lawn to be unappealing. A thick healthy turf with no bare spots will exclude cicada killer wasps. If turf is thin in nesting areas, identify turf problems that make the turf weak and correct them.
Cicada killer wasps will be active for only a few weeks and will be gone by mid-August in most of Georgia. If someone is bothered by these wasps, late July and early August would be a good time to take their vacation.
For more on cicada killer wasps, see these articles:
June and July are excellent times to prevent white grubs in turf. White grubs live in the soil and feed on the roots of turf. Most white grubs have a one year life cycle in Georgia. Adult beetles lay eggs in late spring or early summer. The eggs hatch into grubs which feed and grow through the summer and fall, then dig down to spend the winter deep in the soil. They become active as the soil warms in the spring, and feed for a few days to a few weeks, depending on the species. They then turn into pupae before emerging as adult beetles to continue the cycle.
White grub larvae
White grubs are the immature stage of Scarab beetles like green June beetles, Japanese beetles, chafers and others. The scarabs are a large family of beetles, and there are perhaps two dozen different species of white grub that might be found feeding on the roots of turf in Georgia. Included in this group are some of the most serious insect pests a turf manager will face.
White grubs damage turf by feeding on the roots during the summer and fall and, to a lesser extent, in the spring before pupation. Very dry conditions can reduce survival of both eggs and small grubs.
White grub injury on turf
Symptoms of white grub damage are similar to other factors that damage the root system – disease, soil compaction, poor fertility, or drought. Except for the green June beetle, grubs never come to the surface until they become adults. The only way to tell if a lawn is infested is to dig the grubs up.
To scout for white grubs, cut 3 sides of a square of turf and lay the grass back like a carpet. Dig gently in the soil to a depth of 4 inches and count the grubs you see. It is important to identify the grubs before you treat. The potential for turf damage is dependent on the number and types of white grubs present. Your county agent can help identify grubs or see the publication White Grub Pests of Turfgrasson the CAES Entomology Department website.
It is easiest to find white grubs in early spring and late summer (late August) when they are larger and easy to see. That is not the best time to treat, however. Treatments are more effective if applied while grubs are small. In most of Georgia, this means application in June or July for best control. Once white grubs get bigger, there are fewer effective options and higher pesticide rates will be required. Good soil moisture and watering in the pesticide is also important for white grub control.
See White Grubs of Turfgrassfor good information on control measures. Consult the Georgia Pest Management Handbook for current pesticide recommendations. Follow all label recommendations when using any pesticide.
Alfredo Martinez, Extension Plant Pathologist and Clint Waltz, Extension Turfgrass Specialist Adapted from original manuscript prepared by Drs. E.A. Brown, Retired UGA Extension Plant Pathologist and G. Landry, Retired UGA Extension Agronomist
Failure to green-up in the spring or successful green-up followed by decline and death in late spring and summer is a problem that can be encountered in centipedegrass-growing areas. Centipedegrass is subject to a condition called “centipedegrass decline.”
Many factors may contribute to this problem. It is important to be aware of these factors so that preventive and/or corrective steps can be taken. This problem can be prevented by proper management, which includes avoiding over-fertilization, preventing thatch accumulation, irrigating during drought stress (particularly in the fall), and maintaining a mowing height of 1 to 1.5 inches.
Do things seem really dry where you are? How much should you water your lawn or irrigate your crops? There are a number of commercial products out there that can help you determine this, but one simple method that is available for free is the Lawn and Garden Moisture Index, a daily map put out by the Alabama State Climatologist based on estimated rainfall from radar. This map tells you whether your lawn and garden have enough moisture or if more needs to be added. This is one of a number of useful products available on AgroClimate.org, a website developed by the Southeast Climate Consortium, a group of eight universities around the Southeast.
This map shows the areas with surplus water in greens (no need to water or irrigate there) and areas with a water deficit in oranges and reds. The darkest red areas are almost 2 inches short of water, including a large portion of Georgia. If this situation continues, then the Drought Monitor is likely to add D0, abnormally dry conditions, to the next weekly Drought Monitor map. Areas with deficits of an inch or more should be irrigated to help alleviate the dry conditions and keep lawns and gardens healthy.
Common lespedeza in a centipedegrass lawn. Photo by Patrick McCullough.
This weed is common lespedeza. To learn about is biology and control, see this publication by Patrick McCullough, UGA Extension Weed Specialist. This information is taken from his publication.
Common lespedeza (Kummerowia striata (Thunb.) Schind syn. Lespedeza striata) is a freely-branched summer annual legume that is a problem weed in lawns and other turf areas. Common lespedeza, also known as Japanese clover or annual lespedeza, has three smooth, oblong leaflets with parallel veins that are nearly perpendicular to the midvein
Common lespedeza woody stems in late summer. Photo by P. McCullough.
As common lespedeza matures, the stems harden and become woody, which is attributed to persistence and competition with turfgrasses in late summer
Flowers are pink to purple and present in the leaf axils. Other lespedeza species may also be found as weeds in turf but common lespedeza is the primary species in Georgia.
Leaf of common lespedeza. Photo by Patrick McCullough
