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)
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/.
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 May through August. 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 2016 has delivered hot and dry weather with less than normal rainfall. With August approaching, now is the time to fine tune your turf management program to salvage an acceptable appearance while minimizing growth until environmental factors improve.
The first order of business is to recognize moisture stress in turfgrasses in the early stages. Look for areas with a dull bluish-gray cast. Additionally, take note of footprints and tire tracks in the turf that do not seem to rebound.
Dr. Clint Waltz, UGA Extension Turfgrass Specialist, suggests these tips for managing turfgrass during drought periods:
Raise the cutting height within the recommended mowing range
Reduce fertilizer applications until conditions improve
Modify herbicide programs during high temperatures and moisture stress
Water deeply & Infrequently
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.
Reduce Nitrogen Applications
Plant growth requires water. Without water, the benefits of nitrogen are not optimized and you may be wasting product. Promoting heavy top growth amidst drought conditions increases water demand. Reduce rates or postpone fertilizer applications until environmental conditions improve to fully realize the benefits of fertilizer while saving water and reducing turfgrass stress.
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. As of July 26, 2016 there are no official declarations of drought by state or local authorities in Georgia and responsible landscape and lawn watering may take place between the hours of 4:00pm and 10:00am in accordance with the Georgia Water Stewardship Act of 2010. In the event that water resources require a drought response level 2, watering programs would need to be adjusted for the odd-even schedule by address.
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 certified cultivars such as TifTuf bermuda. Visit www.GeorgiaTurf.com for more information on selecting turfgrasses.
Following a late winter or early spring pruning of Maple, Birch, Elm, or Grapevines it is common to observe “bleeding” from the pruning wounds. This phenomenon usually occurs just before and during leaf emergence in the spring, especially during years of abundant soil moisture. The temporary bleeding is generally not detrimental to the health of the plant and primarily consists of a watery sap solution. The bleeding usually ceases once the leaves have fully emerged and water begins to evaporate through the leaf stomata, creating transpirational pull that overshadows the root pressure.
The upward flow of water is caused by osmotic pressure in the root system that begins with the imbalance of water molecules between the soil and the root system. A high concentration of minerals and carbohydrates in the root system generally translates to a lower concentration of water molecules when compared to the surrounding soil. Water molecules enter the root cells to equalize distribution, causing root cells to become turgid and force water upwards in the vascular system. (Incidentally, the reverse is true when too much fertilizer is applied and a higher concentration of minerals in the soil prevents the osmotic absorption of water into the root system.)
Occasionally, bleeding can be a nuisance where these plants drip on parked cars and pedestrian spaces. In such cases, delay pruning of these species until late spring-early summer to help to reduce the issue.
If prolonged bleeding occurs and you observe any unusual signs or symptoms of pests or disease, report the information to your local extension agent for further assessment.
Frank Watson is the University of Georgia Extension Agent in Wilkes County
Landscape plants get plenty of attention during the summer, but they need protection during Georgia’s winter months. Rather than trying to keep plants warm, gardeners should help protect plants from wind, snow, ice, drastic soil temperature changes and heat from the sun on cold days.
Reducing water loss can protect evergreen plants. All plants transpire, or lose, water through their leaves. Evergreens continue to lose water during the winter, so the plant’s roots must be able take up moisture.
Homeowners are more conscious of watering shrubs during the summer and often neglect to water plants during cold weather. Roots absorb moisture when it’s available, but during a dry period or even when the ground is frozen, moisture isn’t available. The plants continue to transpire water, drawing moisture from living cells. If too much water is released, the plant’s cells die, causing the plant’s leaves to turn brown and die.
High winds and warm sunshine on cold days result in a higher rate of water transpiration. Protection can be offered by relocating susceptible plants to a sheltered location. Also, provide them additional water during dry periods or prior to expected hard freezes.
An additional layer of mulch is also recommended during winter months after the first freeze. Mulch will reduce water loss from the soil, aid in transpiration and reduce “heaving” of the soil as the ground freezes and thaws. Soil heaving, or frost heaving, occurs when soil swells during freezing conditions and ice grows towards the soil’s surface.
To protect plants from cold damage, University of Georgia Extension horticulturists recommend following these six steps:
Given a choice, plant less-hardy plants in the highest part of the landscape. Cold air settles in the lowest area.
Protect plants from cold wind with a fence or a tall evergreen hedge of trees or shrubs.
Shade plants from direct winter sun, especially early morning sunshine. Plants that freeze slowly and thaw slowly will be damaged the least. The south side of the house, where there is no shade, is the worse place to plant tender plants.
Stop feeding plants quickly available nitrogen in late summer to allow them to “harden off” before cold weather arrives.
Plastic covering provides excellent protection. Build a frame over the plant or plants, cover them with plastic and secure the plastic to the ground with soil. Shade plastic to keep temperatures from building up inside. Plastic traps moisture and warm air as it radiates from the soil and blocks cold winds. Do not allow the plastic to touch plants.
Does your landscape business slow down in the fall? Look for services to sell to your customers and ways to more profitably use your time! This could help you to maintain profitability in a slower time of the year, to build your client base and to prepare for next spring.
Fall and winter can be good times to . . .
Offer to conduct a sprinkler performance test. Put a grid of cups across the lawn and run the system through one cycle. Is the amount of water in each cup about the same? If not, water distribution may be uneven which can lead to landscape issues. Look for leaks, controller problems, blocked or broken heads, misadjusted heads etc. Find the problems causing uneven distribution and fix them. Offering a sprinkler diagnostic service to your clients can help them to conserve water, improve landscape health and save money.
Re-set sprinkler systems so they run less often. Typically once a week should be plenty in the fall. Apply three-quarter to one inch of water every time you irrigate. Wait until the soil dries to water again. Once the winter rains begin, we can usually turn the systems off for the winter unless there are new plants in the landscape. In the colder areas of Georgia, you may need to drain the sprinkler system so it will not be damaged during a freeze this winter.
Offer a special on irrigation installation in the off-season.
Plant or move woody trees, shrubs, and many perennials. Late fall and winter is generally the best time to plant woody plants and many perennials. Planting in the cooler, wetter weather gives the roots time to get well established before they have to deal with our harsh, dry summer weather!
Soil sample to look for low pH or fertility problems. This is especially important with St. Augustine, Bermuda and zoysia lawns but can be helpful in many situations. Your local UGA Extension Office can help with soil analysis.
Keep the leaves cleaned up from turf. This will prevent matting during rains which can smother the grass. And it will prevent you having to explain to the homeowner why the lawn died in that area during the winter!
Offer a ‘clean up’ special for new clients needing help with fall leaves and clean-up. Use this as an opportunity to give them a free estimate for maintenance or weed control for the coming year. Perhaps you could offer them a discount for paying ahead for a full year of weed control.
Offer a special on installing hardscapes, outdoor living spaces or lighting or other services that you offer. See if you can move some of the ‘spring rush’ business to a slower time of the year.
Check trees and identify hazards that need to be dealt with. Trees are easier to evaluate for hazards when they have no leaves. Let a certified arborist handle tree issues since tree work is hazardous. Working on trees without the proper training and equipment can open your company to large safety and liability problems. Sub-contract tree work if you do not have fully trained, equipped and insured tree professionals on staff.
Conduct needed maintenance on your equipment. You may be surprised how much better a sharp mower blade cuts a lawn. Sharp blades produce a cleaner cut and a healthier lawn! Winterize equipment that you will not be using this winter.
Conduct inspections of established clients to evaluate the quality of your work, to get client feedback and to look for other services they may need. An online survey is a good evaluation tool as well, but get experienced help designing and interpreting a survey. And if you ask for client feedback, be prepared to make some changes!
Check mulched beds and add mulch if needed. Mulches to prevent weeds and conserve moisture should be 2 to 4 inches thick. Coarse textured mulches (pine bark and wood chips) are better used deeper (3 to 4 inches deep) while fine-textured mulches (pine straw and mini-bark nuggets) are better applied 2 to 3 inches deep. Do not pile mulch around the base of trees or shrubs since this can permanently damage the plant.
These are valuable services you can offer your clients and may be a way of helping you retain business and workers during a slower time of the year.
If you have ideas for increasing fall sales that you would like to share let us know!
Ellen Bauske, Rolando Orellana, and Alfredo Martinez-Espinoza
These checklists can be used to introduce new landscape workers to safe work practices. They ensure that job training includes safety instruction. Before new employees start their first assignment, supervisors should discuss the items covered in the following checklists. Safe use of equipment and personal protective equipment (PPE) should be demonstrated as the supervisor reviews the checklists. Pictures associated with each item reinforce the safety message for employees.
These checklists are based on the book Safety for Hispanic Landscape Workers which has been approved by OSHA for use in safety training. They are designed to help companies reduce incidents, stay in compliance and create a culture of safety.
As you receive the Landscape Alert emails, we want you to use this information from UGA to continue to improve the services you offer and to give you a competitive advantage in the landscape and turf industry. Here are some ideas on how to do this:
When you receive an Alert on a recent pest outbreak:
Use the Alert information to train workers how to look for this pest and how to determine if some type of control is needed. This may offer the opportunity for a sale to your customer.
If you see the pest in a landscape, notify the client that you have found this pest and if there is any need for concern. Even if you do not have to manage the pest, the client will appreciate this information and this will build your rapport with your client.
Leave a copy of the specific Alert on that pest with the client or direct them to the Alerts.
Link to the Alerts on your website or re-issue the Alerts to your customers in your own email newsletter, as a mail out, etc. Please keep the original author’s information on whatever you publish so the readers will know the information comes from UGA.
Use Alerts for training workers (especially on rainy days!)
You could also make a notebook of pertinent Alerts and other information and put it in every vehicle to use to identify problems.
Train workers using the online bilingual safety videos
If an Alert mentions that it is time for a particular type of service (aerating, planting, seeding, mulching, etc.) then begin to promote that service with your customers.
Information from UGA will help the customer understand the importance of performing these services at the right time of the year and can lead to further sales for your business. These turf calendars can also help with this.
Alerts can help you to train your customers.
Some customers may not realize the need to follow recommendations that you make concerning proper watering, timely maintenance, etc.
Many landscape problems are actually due to improper care. Information from the Alerts or other UGA publications can help you to make your point when you encourage homeowners concerning their responsibilities to properly maintain their landscapes. This might include proper watering, mowing, pruning, fertilization, etc. You could also train the client to look out for certain types of pests or other problems and then to contact you for control measures.
Landscape Alert readers also receive information on upcoming trainings and events.
Keep your certifications up to date with these trainings.
Make certain your clients know of your certifications, memberships and trainings you attend so they will realize the ongoing training you receive. You could publish a short article once a year to let clients know of your ongoing training or of recent certifications that employees receive.
Have you winterized your trees yet? Fall is a time of serious change and reorganization within a tree. Many trees will not survive to grow in another spring. You can help your trees survive and thrive.
Winter is a difficult time for trees. Trees must stand in the face of drying and cold winds. Food reserves must be carefully conserved for the coming needs of spring. Water continues to be lost from the tree. Any creature needing a meal chews and nibbles on the resting buds and twigs. Trees stand alone against all circumstances that the winter season can generate.
A few small investments now can pay-off in a large way, yielding a healthy and structurally sound tree.
The “Top 10 List” of things you can do to winterize your tree include:
Remove or correct structural faults and deadwood that are clearly visible. Try to make small pruning cuts that minimize the exposure of the central heartwood core on branches.
Properly prune branches that will touch the ground when loaded with rain and snow. Foliage and branches that are in contact with soil can invite undesirable pests and problems.
Remove damaged and declining twigs, branches, and bark. Do not leave pests food and shelter for the winter.
Remove any new sprouts that have grown at the tree base, or along stems and branches. Pruning should conserve as many living branches as possible with only a few selective cuts.
Spread a thin layer of composted organic mulch to blanket the soil. Cover an area at least as large as the branch spread. Mulch is nature’s of recycling valuable materials, but be careful of pests hitching a ride.
Properly wrap new trees that have not developed a corky bark and could be easily damaged. Mechanical injury from the environment, including chewing and rubbing by animals, must be prevented.
Aerate soils if they are compacted and poorly drained. It is critical not to damage tree roots in the soil. Saturated and dense soil can suffocate roots.
Fertilize with all the essential elements, if they are in short supply within the soil. Be sure to go lightly with nitrogen, especially under large, mature trees and around newly planted trees.
Watering may be needed where soils are cool but not frozen, and there has been little precipitation. Winter droughts need treatment with water the same as summer droughts, except it is much easier to over-water in winter.
Trees are investments that require a small amount of care. For the sake of your tree’s quality of life and your own, take a few minutes to winterize your tree. Wonderful springs come from well-tended winters.
Bodie Pennisi, Department of Horticulture and Willie Chance, Center for Urban Agriculture
Well-groomed landscapes are often a result of considerable effort by landscape companies. Employees make them happen with routine care and, above all, attention to detail. A quality landscape and the image employees present on the job speak highly of the professionalism of the firm. Quality control (QC) is everyone’s responsibility and an essential part of a landscaper’s job. This publication describes the basics of creating and implementing a successful QC program for your landscaping company. See the entire publication