Gray Leaf Spot: Should You Be Concerned?


Gray Leaf Spot is beginning to show activity on St. Augustine lawns in the south and southeastern parts of the country. This is an important infectious disease and can also occur on cool-season grasses, Tall Fescue and Perennial Ryegrass, although it generally shows up on those grasses later in the summer.

This disease shows up on St. Augustine when the weather becomes hot and humid. It affects the turf by severely blighting and defoliating the leaves of the grass, but does not affect the roots. It is more of a problem on lawns that receive excessive amounts of nitrogen fertilizer during the summer months, so be careful about adding too much nitrogen to your lawn in the heat of the summer.

5 Contributing Factors:

  1. Soil compaction
  2. Improper irrigation practices
  3. Watering at night – the disease can spread rapidly when it has temperatures of 85° or higher.
  4. Humidity
  5. Time of the year: specifically, June through September


On St. Augustine, symptoms of the disease include leaf spots with reddish brown borders. The center of the spot takes on a tan color and they may grow together to form large blighted areas. It gets its name from the gray fungal growth, that resembles gray velvet, which appears on these spots during wet, humid weather.

gray leaf spot

When the spots become numerous, the entire leaf may wither and die.  The turf will take on a blighted or scorched look. Some patches will develop more of the disease than other areas of the lawn. These spots can be confused with drought stress or even insect activity.


There are disease control treatments that can be applied if the disease is caught early. Once the grass blades start to die off, it becomes much harder to help the lawn recover. One thing to remember is that the grass blades that have the disease will need to drop off. New grass blades that grow in their place will have less or none of the disease symptoms present.

Sometimes customers ask about the amount of fertilizer that is applied to a lawn and ask whether it is causing the particular type of disease to occur. It is a very good question. Spring-Green’s lawn care programs are adapted to the type of turf grass that is being treated.

We have worked with university consultants, product manufacturers and industry experts to put together lawn and care programs that meet the needs of the turf and provide the results that our customers desire. It is never a good idea to try to supplement our programs by adding additional fertilizer on your own. We guarantee results for our full program customers. If you are unhappy with results, contact us and we will work with you to make it right or we will refund your money for that application.

Monitor your lawn for this serious disease. If you suspect your lawn has Gray Leaf Spot, contact your neighborhood lawn care professional at Spring-Green to check your lawn and they can advise you on treatment options.

Be On the Lookout: Large Patch Symptoms Now Showing!

This disease was formerly called Brown Patch, which is a disease that affects cool-season grasses in the middle of the summer.  It is basically the same disease, but Large Patch begins the infection process in the fall and the symptoms show in the late spring early summer. Brown Patch begins to infect cool-season grasses during periods of high heat and humidity and the symptoms immediately show on the lawn.

Large Patch

Large Patch begins to develop when soil temperatures drop to about 70 degrees in the fall. The symptoms of the disease may show in the fall, but more likely they will show during the spring of the following year, especially during cool, wet periods. The symptoms become very noticeable as these grasses start greening up.

Large patch is more likely to show up on lawns that receive excessive nitrogen fertilization in the fall and spring, have excessive thatch layers, have been over-watered or been mowed too low. Centipede-grass is most susceptible to the disease, followed by Zoysia, St Augustine and Bermuda-grass.  Bermuda-grass is rarely affected by the disease and will quickly recover if it does get the disease.

Following good cultural practices of proper mowing, deep and infrequent watering, proper fertilization and annual core aeration will help prevent the disease from occurring.  Avoid fertilizing the lawn after the middle of September and don’t fertilize until the grasses begin greening up in the spring.

There are fungicides that work very well on these diseases, but require two applications in the fall, 30 days apart, when soil temperatures drop to below 70 degrees. The easiest way to check the soil temperature is with a digital meat thermometer, pushed in the ground about two inches in four or five locations throughout the lawn and then average out the temperature readings.

If you think that your lawn may have Large Patch, contact your local Spring-Green office to have your lawn evaluated.  They can help develop a program that will benefit your lawn and help to prevent the re-occurrence of Large Patch.

Watch Out For Large Underwing Moth Larva

Last fall, we described a new turfgrass pest that was causing some damage in the Seattle area.

At the time the article was written, the insect was thought to be an army cutworm. Since that time, we have learned that it is the larva of the Large Underwing Moth.

Underwing Moth larva1

This insect was accidentally introduced from Western Europe and was first founded in 1979 in Nova Scotia, Canada.  According to a bulletin from the University of Idaho’s Extension service, the first moths were collected flying around a porch light in Nova Scotia. There is no information on how it arrived in North America.

The bulletin also stated that once the insect was established, it moved south and west and is a potential threat to winter wheat and barley. What makes it challenging is that it feeds during the winter months, which is the same time as the feeding period of another major turfgrass pest in the Pacific Northwest, the European Crane Fly larva.

Although it is not known to be a major turf grass pest, it will feed on bluegrass from fall through early spring. As you can see from this picture, which was taken in March, the damage can be extensive.

Moth damage

As with other cutworm species, these larva feed during the evening hours and hide during the day. The Black Cutworm, a major insect pest on golf courses, will dig into the soil on greens and tees during the day.

When disturbed, cutworms will curl up into a c-shape. Once they are done feeding, the larvae will burrow into the soil to make a cocoon. They will pupate in May and the adults will emerge and be more active at night. The females will then lay eggs (a single female can lay up to 2,000 eggs) through August, but they can be active all the way until October.

Fortunately, cutworms just feed on the upper part of the grass plant and it usually recovers from such damage. As long as the crown of the plant has not been damaged, the turf will regrow new grass blades.  This can be helped along by fertilizing the lawn.  In severe cases, some reseeding may be necessary.

If you think your lawn may have an insect problem, contact your local Spring-Green office and have them come out to inspect your lawn. It is the best way to keep your lawn looking green.

How to Avoid Green Slimy Ooze From Growing On Your Lawn.

nostoc algae

What is this Green Slimy Ooze?

During the last couple of years, I’ve received several questions about a strange green slimy ooze growing in lawns. So after doing some research, I learned that it is a type of cyanobacterium, formerly called blue-green algae. This green slimy ooze has been called many colorful names over the years, including witches, butter and star jelly, which is based on the belief that the ooze was indeed the remnants of shooting stars.

Why do I have it?

Nostoc Algae will occasionally appear after excessive rain falls and will not only develop on lawns, but also on sidewalks, driveways and other paved surfaces where it can even become a slippery hazard. If it is developing in a lawn, it usually does so in areas where the turf is growing poorly, soil is compacted, area retains moisture or if fertilizers used  are high in phosphorus. The important thing to understand is that the Nostoc Algae is not the cause of the decline in the lawn. It develops in areas that provide the ideal conditions for its growth.

How do I get a rid of it?

Once the Nostoc Algae develops in a lawn, it can be very difficult to remove. The gelatinous mass will dry up into a black crust that reforms when favorable conditions return. If you have seen this grow in your lawn, the best solution is to improve the growing conditions where the algae developed. This may include improving the drainage in the area.  Core aeration is a great process to help reduce compaction. Unfortunately, there is a risk that the algae will be distributed to other parts of the lawn during the aeration process. This may require applying a moss and algae control product to your lawn as a supplement to core aeration.

There are several commercially available moss and algae control products available at hardware stores and garden centers.  Be sure to follow all label directions when using these products. If the algae forms on paved surfaces, use a shovel to scoop it up and throw it away.

Nostoc is not a very common problem. I have never actually seen it on a lawn and have only seen pictures of it.  Normally this problem develops in late spring. But the picture above was sent to me by a manager of our Baton Rouge, LA office from when he observed it in December. As mentioned in a previous blog post, if the conditions are right for a disease to develop, and algae could be included in the disease family, it will develop.

Do you think you might have Nostoc Algae in your yard? Let us know by either commenting below or asking your local Spring-Green.

What Causes A Lawn Disease To Develop?

Hand on Green Grass

In order for a lawn disease to develop, three conditions – known as the Disease Triangle – must exist.

1. You need to have the pathogen or disease-causing agent present. Disease spores from the diseases that are common to the area can be found in most home lawns. They usually float in on wind currents, wash in during rain events or are transmitted by animals or people.
2. You need the host plant, which is your turf grass (or tree or shrub). Usually the plant needs to be actively growing in order for the disease to infect it.
3. Finally the third side of the triangle is the environment. When we speak about the environment, we are referring to air temperature and moisture, but still other environmental influences came into play. Mowing too short, letting the turf grow too long, too much fertilizer, too little fertilizer, too much water, too little water, too much shade, poor soil conditions, variety or cultivar of the plant, etc.

However the thing that brings it all together is time. The environment has to exist for a long enough time for the pathogen to develop and infect the host plant. If proper cultural practices are being followed, meaning proper mowing, watering, fertilization and thatch control, the likelihood of a disease developing is greatly reduced – but not eliminated. If conditions are perfect for a long enough time for a disease to develop, that is what it will do.

Case in Point: Red Thread Lawn Disease

This is exactly what happened during the warm spell much of the nation experienced in December. Two of our lawn care franchise owners, Scott Bixby of Wilmington, DE and Charlie Marshall of Centreville, VA, sent in pictures of a disease that is normally seen in the late spring or early summer – Red Thread.

Lawn Disease

For those of us in the lawn care industry, seeing something out of the ordinary is a welcome diversion. However it may not be the same case for our customers. Now that the weather has turned more seasonal, the development of Red Thread has stopped, however the spots will remain until it begins to warm up again. There really is nothing that can be done at this time of year. Marvel at the wonders of nature and dream about warmer days to come. At least that is what I am going to do.

Are you seeing other lawn diseases in your yard? Find your local Spring-Green owner to discuss treatment options and our satisfaction-guaranteed lawn care services.

Snow Mold: What It Is and How to Treat It

grey snow mold

It is early spring and the snow is beginning to melt, often bringing outbreaks of Snow Mold on many lawns. Although it is not a serious disease, snow mold can leave large destroyed areas on a lawn that will take a lot longer to turn green as the weather continues to warm up.

What Is Snow Mold?

There are two basic types of Snow Mold – Grey and Pink – named after the color that the mycelium, or fungal growths, turn as they are exposed to sunlight. Despite its name, Snow Mold can develop without snow cover. Activity is greater when temperatures are between 32 and 45 degrees with cloudy, cool, and wet weather… or in other words—spring. Both diseases can occur at the same time in the same lawn if the conditions are right.

On warm season grasses, Pink Snow Mold is called by a much more ominous-sounding name, Microdochium Patch. It is the name given to Pink Snow Mold that occurs on warm-season grasses like Bermudagrass. It is basically the same disease and they both develop pinkish mycelium. The process of developing this mycelium is often referred to as “flocking.”

pink snow mold

What Is the Best Snow Mold Treatment?

Usually by the time you get out to see if you have Pink Snow Mold, the pink color has faded away. What you will see are small, 6- to 12-inch patches of turf that appears to be glued or matted together. If there are just a few patches, the best snow mold treatment is simply running your fingers across the area to break up the matted turf. If the area is larger, you may have to likely rake the area to break up the matted turf.

Is Treatment the Same for Grey Snow Mold?

Grey Snow Mold more closely matches its name. This disease will create mats of dense mycelium, which resembles thick cobwebs spread across the turf. Many times, once the sun comes out, the mycelium will dry up and disappear. As with Pink Snow Mold, the turf may mat down, requiring some light raking.

If you are not sure what type of Snow Mold may be in your lawn, or if you even have it, contact your local Spring-Green office to have them come out to check your lawn. They can provide you with an accurate diagnosis and provide you with additional treatment options.

Lawn Diseases: Caring for Warm Season Grasses Like Centipede Grass

Lawn disease solutions for warm season grasses

I recently attended the South Carolina Landscape and Turfgrass Association annual conference and tradeshow in Columbia, SC for the second year now. Since I’ve lived most of my life in northern Illinois, I always welcome the chance to learn more about warm-season grasses, and this show provides some appreciated insight.

Warm Season Lawn Disease: Centipede Decline

One of the presentations I attended was about warm-season grass disease. Centipede grass is grown in many home lawns throughout the South and requires less fertilizer than many other warm-season grasses—it’s also prone to two diseases: Large Patch and Centipede Decline. The speaker, Dr. Bruce Martin from Clemson University, explained that Centipede Decline is considered a man-made disease, often brought on by homeowners who seem to follow the “if a little is good, a lot is better” school of thought on centipede grass care. Too much water, improper mowing and too much fertilizer will often lead to this lawn disease. It is more of a condition brought on by too much outside stimulus.

When speaking with our franchise owners in the southern states, they’ve told us that several homeowners have contacted them for help after they have tried and failed at caring for their own Centipede grass lawn. At that point, it is an uphill battle to get the lawn back into shape. Fortunately, our owners have the experience and knowledge to help improve these warm season grass lawns.

Warm Season Lawn Disease: Large Patch

Large Patch disease (formerly known as Brown Patch) occurs in the cooler weather of fall through early spring on warm-season grasses. It can infect Centipede, St. Augustine, Bermuda and Zoysia grasses. (Brown Patch, in contrast, occurs during the heat and humidity of summer and is often found on Tall Fescue lawns.) Large patch appears mostly in circular patches that are yellow to tan in color. They start off small—2 to 3 feet in diameter—but can quickly expand to 10 feet or more in diameter. The patches can grow together to form even larger patches, which is where it gets the name “Large Patch.”

To determine if Large Patch is happening on a lawn, you have to look for spots or lesions on the grass plants. It may be necessary to peel back the dead, older leaves to see the lesions. Disease-control materials are available to treat this lawn disease, but the treatments need to start in the fall when soil temperatures fall to about 70 degrees.

Not only were there sessions on warm-season grasses, but there were also sessions on tree care, such as caring for palm trees. South Carolina is known as the Palmetto State, named for the Sabal Palm that grows along the coast. The botanical name for the Sabal Palm is Sabal Palmetto, which is where it got its name. It is more commonly called the Cabbage Palm and can grow as high as 80 feet. One of the interesting things I learned about these trees is that the wood is soft and spongy, not dense like a regular deciduous tree. These trees were used to construct a fort during the Revolutionary War—the British became frustrated when their cannonballs would not penetrate the walls, but just bounced off… but I digress.

Spring-Green: Staying Up to Date on Lawn Care Research

Even though I have been working in lawn care for over 37 years, I always find that I can learn new information and enjoy attending these regional conferences. In addition to validating what I already know, I always learn new techniques and recommendations. There is a good deal of research on turfgrass being done at universities across the United States, and staying up to date on the latest information is a value to our franchise owners—especially in regards to the customers that they service.

Want to learn more about warm season grasses or other problems affecting your yard? Ask your local Spring-Green professional to come out for a free estimate!

Preventing Lawn Rust and Rust Disease


August is here, and so is Rust. If you live in the Midwest, you’ve been enjoying a year with an abundance of rain—except for the last three weeks. If you’ve noticed that your lawn mower appears to be covered with an orange-colored powder or that your white tennis shoes have turned orange after mowing your lawn, then your lawn has developed rust.

Rust disease is common on cool-season grasses, especially perennial ryegrass, that often develops in the late summer, especially if there has been a good deal of rain followed by a dry period. The disease first appears as yellow to orange stripes on the grass blades. As rust disease progresses, it will erupt through the walls of the grass blades, releasing millions of spores into the lawn and into the atmosphere.

Rust does not occur every year, but when conditions are right, it can become a big problem.

If you’re seeing Rust in your lawn, it’s too late to apply disease control, as the disease has already run its course. You would’ve had to apply a disease control material three weeks ago to prevent the disease from occurring. The best thing to do is fertilize your lawn to stimulate new growth and mow off the damaged blades. You can collect the clippings to try to reduce the amount of spore distribution, but there will still be plenty left behind, so it’s not really necessary.

Your lawn will recover on its own, but it will recover faster if it is fertilized. If rain is not forecasted, water after fertilizing. It’s also a good idea to aerate the lawn this fall and overseed with disease-resistant cultivars of perennial ryegrass and bluegrass to ensure your lawn is in great shape for next spring. Want some help with your lawn maintenance? Contact your local Spring-Green today!

Ascochyta Leaf Blight Lawn Disease

For the last several years, a minor disease has been affecting many lawns during the late spring into the early summer:

• It usually occurs during the period of time when the weather switches from cool and wet to hot and humid.

• Lawns have been growing well and then heat and humidity blankets the area.

• Mowing during the heat of the day seems to be one of the factors that cause this disease to become active.

• It mainly affects bluegrass and it is usually on lawns that were mowed too short.

The lawn disease is called Ascochyta Leaf Blight.

The one good thing about this disease is that it is not a crown killer and the plant will recover on its own. If you see sections of your lawn that look like the picture above, you will notice that the grass blades have turned tan from the tip down, but are green at the base. The turf will recover, but it will take a couple of weeks. Since it has been dry, water will help the grass recover at a faster rate. A fungicide will not help as the disease has already done its damage.

Many times, buried debris or other structures lurk a couple of inches below the surface and can present some unusual shapes in a lawn, such as what you see in this picture. Although it may look like a lawn disease , it sometimes isn’t. It is fairly easy to see that there is something square located just underneath the ground. My guess is that it is some sort of utility structure buried in that area.

In my years of working on suburban lawns, I have found 4 X 8 sheets of plywood, old sidewalks and patio blocks, as well as many other items, that show up as the weather turns dry. If any of you have a septic system, you are very familiar with the lines of dry grass that form where the drainage tiles are located. There are times when you have to use some detective skills to determine the cause of brown spots in a lawn.

If your lawn has suffered from ascochyta leaf blight, or if you’re looking to identify and repair another lawn disease, contact your local Spring-Green lawn care team.

Red Thread Lawn Disease

Red Thread Lawn Disease – A Serious Disease, But Not Too Serious

One of my favorite diseases is Red Thread as it is one of the easiest disease to identify.  What makes it so is the pinkish-red color that is an indicator of its activity.  Upon careful examination, you may see a thin antler-like structure protruding through the tip of the leaf blade, which may resemble a tiny thread.  This is how the disease gets its one of its names – Red Thread.  There is a similar disease, Pink Patch, that develops masses of pink fungal hyphae in the thatch or on the leaf blades.  Both of these diseases can occur at the same time.

Red Thread can develop in both spring and fall, but it is generally considered a late spring disease.  Temperatures that favor its development is between 40 to 70 degrees with long evening dew periods.  It has long been associated with weak, under-nourished turf, it can quickly develop even on well managed turf as well.  The spores of the disease remain in the thatch during none-active periods and will begin to develop when conditions are right.

The damage that Red Thread causes can be unsightly, but the symptoms are temporary as the disease does not affect the crown or roots.  Many times, a supplemental lawn fertilization will help the turf “grow out” of the disease and it will return to normal in a short period of time.  Disease control treatments are usually not necessary as once the disease activity is seen, it is basically run its course and the turf will recover on its own.  If it is a re-occurring problem, a spring application of a disease control material may be recommended.