Winter Advisory! Understanding Turf Grass Winterkill

December 20, 2017

A major concern for green industry professionals is damage or loss of turf grass due to colder winter weather. As the temperature outside drops, you may be worried about your turf experiencing harm from these harsher seasonal conditions like winterkill. What’s amazing about turf grass is that it naturally tries to prepare and adapt to winter to prevent damage or death. This preparation for cool weather is called cold acclimation. This term refers to turf grasses' ability to make changes to help it tolerate lower temperatures and prevent ice accumulation in plant cells (ice accumulation can result in cells rupturing which injures the plant). During the cold acclimation process of turf grass, it accumulates certain sugars and proteins to create a cell wall that becomes more fluid and allows for plant cells to dehydrate in order to become hardier over winter. Colder winter weather brings challenges for both cool season and warm season turf grass. Although both species have the ability to prepare themselves for winter, there are still multiple factors that may arise that can cause damage or even death to turf. 

WHAT IS WINTERKILL?
Winterkill is an all-inclusive term that is used to describe the various causes of turf loss over the cool winter months. Winterkill can happen due to a combination of factors including low-temperature kill, ice sheets, desiccation, crown hydration, and disease.

LOW-TEMPERATURE KILL
Extreme cold can produce the winterkill problem known as the low-temperature kill. Low-temperature kill can happen on two different levels; on the surface and below the surface. Low temperature kill above the surface is caused by ice crystal formation on plant cells at temperatures below 32˚F. The ice accumulation can result in plant cells rupturing which ultimately can cause injury and even death to the plant. Above the surface, low-temperature kill is more likely to happen prior to below surface low-temperature kill. Soil temperatures fluctuate less than air temperatures, insulating the crown (the growing point) of the plant and its roots from winter temperatures. Unfortunately, soil temperature can still drop to a point where damage is done below the surface parts of the plant.

Another issue that can lead to low-temperature kill and interfere with turf grass winter survival is the freeze/thaw cycle. When freezing and thawing happens rapidly throughout the winter months, damage can increase because there is more stress to the plant.

ICE SHEETS
Ice sheets or ice accumulation on turf grass can result in plant death if left on turf for a sustained period of time. Different turf grass species have different hardiness to ice sheet build up, for example, annual bluegrass experiences damage between 45-90 days of ice accumulation while creeping bentgrass can withstand ice until 90-120 days before plant death occurs. Ice sheets cause death because it prevents gas exchange, increasing carbon dioxide to toxic levels.

DESICCATION
Desiccation, also known as winter drought, is the term used to describe turf grass death due to drying out over the course of winter when the grass is dormant or semi-dormant. Desiccation is more likely to appear in areas where soil was dry prior to entering winter or where there has been little snow precipitation or cover throughout the cool winter months. 
  • NOTE: In regions where drought occurs regularly throughout the season, desiccation is more likely to be prominent (i.e. the Dakotas, Kansas, Nebraska and others).
CROWN HYDRATION
Crown hydration injury occurs during the warmer days of winter when temperatures increase enough that turf grass awakes from dormancy and begins to take up water again. Damage happens when a day or two of warm daytime temperatures arrive, followed by the continuation of freezing temperatures. Damage or death to turf happens because of ice crystallization forming within the plant, causing stress and rupturing to the plant's cells. Crown hydration commonly takes place during late winter/early spring when snow or rain occurs and then freezing temperatures return but the melted snow or rain has not fully drained away. 
  • PRO TIP: Cool season grasses are especially susceptible to crown hydration injury since they’re more likely to awake from winter dormancy at the first break of warmer temperatures. 
DISEASE
The most common two diseases caused from winterkill is snow mold ; gray and pink snow mold. Areas of turf grass that appear to be “glued” together, pale yellow in color and have a straw-like quality may be affected by snow mold. Although snow mold doesn’t occur every year, it is not uncommon to find it in turf grass in years when early and deep snow prevented the ground from freezing. The fungal growth from snow mold can cause winterkill injury, causing grass to take a little longer to green up.

Spring dead spot (SDS) is another common winter kill fungal disease in the warm season species, bermudagrass (although less common, spring dead spot can be found in zoysiagrass). This disease can be identified by its well-defined circular patches of bleached out, dead turf. This disease can become evident when turf begins to green-up in spring. This is a destructive, persistent disease that happens when turf is exposed to freezing temperatures for extended periods of time. The fungi of SDS are active in fall and spring when conditions are cool and moist. The fungi don’t actually kill turf directly but instead weakens the turf by feeding on grass roots, rhizomes, and stolons, making it more susceptible to winterkill injury. SDS fungi can infect turf anywhere from temperatures above 50° F to below 70°F. 

A patch of brown grass on a lush green lawn.

Spring Dead Spot Fungal Disease

 RECOVERING FROM MODERATE - SEVERE WINTERKILL Unfortunately, winterkill damage cannot be fully assessed until turf grass goes through its spring green-up and warmer weather returns. If spring arrives and you notice some damage from winterkill, sodding or seeding may be necessary to help with turf grass recovery. Prior to seeding it is crucial to understand your region and which grasses will thrive. 


 *IMPORTANT* NEVER USE A PRE-EMERGENT HERBICIDE WHILE SEEDING/SODDING. PRE-EMERGENT HERBICIDES WILL KILL GERMINATING GRASS SEEDS. 


Predicting winterkill is not something you can always forecast since a variety of winterkill damage is caused by seasonal factors out of our control. By choosing a thriving and adaptable turf grass species and maintaining good turf care practices, turf grass can avoid winterkill and defend itself against the cool, harsher winter weather. 


Winterkill prevention on turf can be helped with a healthy, dense turf and a strong root system with a regular lawn care routine including fertilization, soil amendments, proper mowing and watering as well as aeration and thatch management practices. It is also extremely helpful to take the necessary steps to “winterizer” your lawn for a hardier winter lawn and a quick spring green-up".


 For professional fertilizers, humic and AMP-XC™ enriched products available, please visit TurfCare’s online Product Catalog.
  
 For green industry professionals or others interested in ordering Turfcare products, please contact our Customer Service to find a distributor near you.

References:
https://www.sportsfieldmanagementmagazine.com/columns/turf-health/protect-turfgrass-winter-damage/
https://www.sportsfieldmanagementmagazine.com/maintenance/winter-weather-forecasting-field-management/
http://plantscience.psu.edu/research/centers/turf/extension/factsheets/cool-season
http://purdueturftips.blogspot.com/2014/03/cool-season-turf-winterkill-potential.html
http://msue.anr.msu.edu/resources/winterkill-of-turfgrass
http://purdueturftips.blogspot.com/2014/03/warm-season-turf-winterkill-2014-what.html
https://www.extension.umn.edu/garden/yard-garden/lawns/snow-molds-in-lawns/
http://extension.uga.edu/publications/detail.html?number=C1012
https://www.clemson.edu/extension/hgic/hot_topics/2016/pdf/09%20preparing_managing_warm_season_grasses_during_the_offseason%202%20col.pdf

Photos:
http://extension.uga.edu/publications/detail.html?number=C1012

The TURFReport Highlights:

Additional Articles and Insights

January 30, 2026
White Plains, NY – January 30, 2026 – Interoceanic Corporation (“IOC”) announced today that its affiliate Spring Valley USA (Spring Valley) , has acquired the blending and packaging assets and business of Turf Care Supply, LLC, a leading manufacturer and blender of turf and ornamental fertilizers as well as ice melt. The combination of Spring Valley and Turf Care Supply’s blending business, forms one of the largest independent lawn and garden fertilizer platforms in North America. The integrated business will have approximately 250 employees and will operate eight manufacturing and blending facilities across seven states, enabling coast-to-coast coverage of customers. By uniting two highly complementary companies, this acquisition creates a world-class turf & ornamental supply company positioned to deliver enhanced value to both professional and retail customers. “This acquisition is a transformative step for our organization,” said Elio Mazzella , President of IOC and Spring Valley. “By bringing Turf Care Supply into the IOC family, we are significantly expanding our reach and capabilities in serving the lawn and garden industry. The combined company will have an unrivaled production footprint and product portfolio, which means we can offer our customers faster service, greater efficiency, and innovative solutions on a national scale. Our goal is to build a world-class platform that blends the strengths of both businesses – the supply chain efficiencies of the combined business and the family-business values – will drive growth for our customers and vendor partners.” With the closing of the transaction, Turf Care Supply, LLC will be renamed Allied Nutrients and continue to manufacture leading enhanced efficiency fertilizers (“EEF”) out of its Martins Ferry, Ohio facility. Mark Mangan, President of Allied Nutrients, commented, “we want to thank our long-time employees that will be joining the IOC family and wish them well. We have known the IOC team for many years and believe this will be a great home. At the same time, we are excited for our remaining employees as we focus our resources and efforts on providing the best EEF solutions to the turf and ornamental market.” With this acquisition, the combined company now operates manufacturing facilities in Wisconsin, Ohio, Texas, Florida, Massachusetts, Tennessee, and Oklahoma, giving it the ability to blend and package fertilizer products and ice melt closer to customers in every major region. Turf Care Supply’s sites in Hatfield (MA), Sebring (FL), Cleveland (TN), and Catoosa (OK) will join Spring Valley’s existing plants in Jackson (WI), Fostoria (OH), Greenville (TX), and Longwood (FL). This expanded footprint significantly reduces transit times and enhances supply reliability for our customers. Maintaining strong customer relationships during and after the integration is a top priority. “All of our customers will continue to receive the outstanding service and product quality they expect, now with the added benefit of a truly national production network,” Mazzella added. Each major customer will be supported by an expanded team dedicated to ensuring a seamless transition and ongoing success. Strategically, the merger of Spring Valley and Turf Care Supply unlocks significant commercial synergies that will benefit both our customers and vendor partners. Together, the company will offer the most comprehensive product portfolio in the industry. “This combination is about building a platform that is perfectly suited to support our customers growth,” said Mazzella. “By combining our R&D and product development efforts, we intend to bring new, high-value solutions to market that neither company could have achieved alone.” The integration of the two businesses is already underway, with a focus on maintaining operational continuity and exceptional customer service throughout the spring season. The company also emphasized that all Turf Care Supply employees are being welcomed into the organization, and that the combined workforce will play a crucial role in driving the business forward. “This is an exciting moment for all of us. By uniting two great teams, we’re creating a stronger company with a shared commitment to our customers’ and vendors success, ” Mazzella noted. About Interoceanic Corporation (IOC): Based in White Plains, NY, IOC is a diversified family-owned company specializing in the production, marketing, and distribution of fertilizer and industrial chemical products. Other notable affiliates of IOC are PCI Nitrogen, Columbia River Nitrogen and EM² Enterprises. With this transaction, the group of businesses consist of over 600 employees. IOC’s family values, entrepreneurial spirit, and supply chain expertise have driven its growth from a regional fertilizer distributor into an international platform that provides reliable, high-quality products. About Allied Nutrients: Based in Brunswick, OH, Allied Nutrients specializes in providing enhanced efficiency fertilizers that support turfgrass and ornamental plant health. Through world-class manufacturing and research and development, the company offers a comprehensive portfolio of products, including SCU, PCU, PCSCU, reacted slow-release nitrogen, and urease inhibitors. 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Turf Care Supply, LLC, a portfolio company of Platte River Equity, has officially acquired Beaty Fertilizer, the industry respected Tennessee-based manufacturer and blender of custom granular and liquid fertilizers, as well as combination products. This strategic move expands Turf Care’s manufacturing footprint, adds new product capabilities, and enhances overall production capacity.
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Dear Valued Industry Partners and Customers, We are pleased to announce that Turf Care Supply, LLC has acquired Agri-Nutrients, Inc. (October 1, 2024) a respected manufacturer in the turf and ornamental fertilizer industry. This acquisition marks a significant step forward in our commitment to providing you with an expanded range of innovative products, services, and industry expertise, all designed to support your business’s continued growth and success. As a valued partner or customer, you will benefit from enhanced service capabilities and an extended geographic reach, thanks to Agri-Nutrients, Inc.’s strategic facility located in the Port of Catoosa, Oklahoma. With this established presence in the Southwest and Western markets, Turf Care Supply, LLC’s expanded operational footprint will allow us to serve a broader region with greater efficiency, delivering even stronger support to help drive your business forward. We are dedicated to ensuring a seamless transition while maintaining the high standards of service you expect. If you have any questions or would like to explore how this new location can enhance your operations, please feel free to contact your account manager or our customer service team. Thank you for your continued trust in Turf Care Supply, LLC . We look forward to partnering with you as we grow together and continue supporting your success. Sincerely, Mark ManganPresidentTurf Care Supply, LLC
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January 30, 2026
White Plains, NY – January 30, 2026 – Interoceanic Corporation (“IOC”) announced today that its affiliate Spring Valley USA (Spring Valley) , has acquired the blending and packaging assets and business of Turf Care Supply, LLC, a leading manufacturer and blender of turf and ornamental fertilizers as well as ice melt. The combination of Spring Valley and Turf Care Supply’s blending business, forms one of the largest independent lawn and garden fertilizer platforms in North America. The integrated business will have approximately 250 employees and will operate eight manufacturing and blending facilities across seven states, enabling coast-to-coast coverage of customers. By uniting two highly complementary companies, this acquisition creates a world-class turf & ornamental supply company positioned to deliver enhanced value to both professional and retail customers. “This acquisition is a transformative step for our organization,” said Elio Mazzella , President of IOC and Spring Valley. “By bringing Turf Care Supply into the IOC family, we are significantly expanding our reach and capabilities in serving the lawn and garden industry. The combined company will have an unrivaled production footprint and product portfolio, which means we can offer our customers faster service, greater efficiency, and innovative solutions on a national scale. Our goal is to build a world-class platform that blends the strengths of both businesses – the supply chain efficiencies of the combined business and the family-business values – will drive growth for our customers and vendor partners.” With the closing of the transaction, Turf Care Supply, LLC will be renamed Allied Nutrients and continue to manufacture leading enhanced efficiency fertilizers (“EEF”) out of its Martins Ferry, Ohio facility. Mark Mangan, President of Allied Nutrients, commented, “we want to thank our long-time employees that will be joining the IOC family and wish them well. We have known the IOC team for many years and believe this will be a great home. At the same time, we are excited for our remaining employees as we focus our resources and efforts on providing the best EEF solutions to the turf and ornamental market.” With this acquisition, the combined company now operates manufacturing facilities in Wisconsin, Ohio, Texas, Florida, Massachusetts, Tennessee, and Oklahoma, giving it the ability to blend and package fertilizer products and ice melt closer to customers in every major region. Turf Care Supply’s sites in Hatfield (MA), Sebring (FL), Cleveland (TN), and Catoosa (OK) will join Spring Valley’s existing plants in Jackson (WI), Fostoria (OH), Greenville (TX), and Longwood (FL). This expanded footprint significantly reduces transit times and enhances supply reliability for our customers. Maintaining strong customer relationships during and after the integration is a top priority. “All of our customers will continue to receive the outstanding service and product quality they expect, now with the added benefit of a truly national production network,” Mazzella added. Each major customer will be supported by an expanded team dedicated to ensuring a seamless transition and ongoing success. Strategically, the merger of Spring Valley and Turf Care Supply unlocks significant commercial synergies that will benefit both our customers and vendor partners. Together, the company will offer the most comprehensive product portfolio in the industry. “This combination is about building a platform that is perfectly suited to support our customers growth,” said Mazzella. “By combining our R&D and product development efforts, we intend to bring new, high-value solutions to market that neither company could have achieved alone.” The integration of the two businesses is already underway, with a focus on maintaining operational continuity and exceptional customer service throughout the spring season. The company also emphasized that all Turf Care Supply employees are being welcomed into the organization, and that the combined workforce will play a crucial role in driving the business forward. “This is an exciting moment for all of us. By uniting two great teams, we’re creating a stronger company with a shared commitment to our customers’ and vendors success, ” Mazzella noted. About Interoceanic Corporation (IOC): Based in White Plains, NY, IOC is a diversified family-owned company specializing in the production, marketing, and distribution of fertilizer and industrial chemical products. Other notable affiliates of IOC are PCI Nitrogen, Columbia River Nitrogen and EM² Enterprises. With this transaction, the group of businesses consist of over 600 employees. IOC’s family values, entrepreneurial spirit, and supply chain expertise have driven its growth from a regional fertilizer distributor into an international platform that provides reliable, high-quality products. About Allied Nutrients: Based in Brunswick, OH, Allied Nutrients specializes in providing enhanced efficiency fertilizers that support turfgrass and ornamental plant health. Through world-class manufacturing and research and development, the company offers a comprehensive portfolio of products, including SCU, PCU, PCSCU, reacted slow-release nitrogen, and urease inhibitors. These solutions are marketed under leading brands, such as XCU, TTRU, UFLEXX, UMAXX, Nutralene, and Nitroform. 
The hidden cost of filler: how to maximize your fertilizer ROI. Shows hand holding filler .
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Want to maximize your ROI and turf health? Ditch the filler and replace your blends with Enhanced Efficiency Fertilizers (EEFs), Micro packs, Soil Amendments, or organic materials. These alternatives can reduce your seasonal application of bags, reduce overall material cost and deliver better results!
A large fertilizer manufacturing facility
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Dear Valued Industry Partners and Customers, We are pleased to announce that Turf Care Supply, LLC has acquired Agri-Nutrients, Inc. (October 1, 2024) a respected manufacturer in the turf and ornamental fertilizer industry. This acquisition marks a significant step forward in our commitment to providing you with an expanded range of innovative products, services, and industry expertise, all designed to support your business’s continued growth and success. As a valued partner or customer, you will benefit from enhanced service capabilities and an extended geographic reach, thanks to Agri-Nutrients, Inc.’s strategic facility located in the Port of Catoosa, Oklahoma. With this established presence in the Southwest and Western markets, Turf Care Supply, LLC’s expanded operational footprint will allow us to serve a broader region with greater efficiency, delivering even stronger support to help drive your business forward. We are dedicated to ensuring a seamless transition while maintaining the high standards of service you expect. If you have any questions or would like to explore how this new location can enhance your operations, please feel free to contact your account manager or our customer service team. Thank you for your continued trust in Turf Care Supply, LLC . We look forward to partnering with you as we grow together and continue supporting your success. Sincerely, Mark ManganPresidentTurf Care Supply, LLC
A forklift is sitting in a garage next to another forklift.
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A person is holding a safety data sheet in front of bottles
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When handling fertilizers and pesticide it is important to follow suggested guidelines and prioritize safety to protect yourself, others, and reduce environmental impact. Here are some general measures to follow: 1.Read and Follow Instructions: Carefully read and understand the product labels, safety data sheets (SDS), and any accompanying instructions provided by the manufacturer. Follow all recommended guidelines, precautions, and application rates.
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