Leaf Spot Lawn Disease On Cool and Warm Season Grasses

leaf spot

There are many different diseases that turfgrasses can contract, but not all turfgrasses get the same diseases, except for one. That disease is called Leaf Spot. There are several different pathogens that cause leaf spot diseases that includes Helminthosporium, Drechslera and Bipolaris. They all belong to a large family of fungi that share the same descriptive name of leaf spots.

The Symptoms and Stages of Leaf Spot

For the most part, the infectious stage of leaf spot fungi occurs during the cool, wet and cloudy weather of spring or fall. Leaf spot can infect all parts of the grass plant; the initial symptoms show up on the grass blades as tan lesions with a reddish-brown border. The term “cigarette burn” is often used to describe the appearance of the lesions. If these cool, cloudy and wet conditions persist for a long time, leaf spot may cause grass blades to turn yellow as the lesions restrict movement of food and water up the grass blades.

The second stage of leaf spot is the more damaging stage. As the disease begins to infect more of the grass plant, the lawn will begin to slowly turn yellow and seem to be “melting” away. This is where the name of the second stage, the melting out stage, gets its name. The melting out stage occurs in early summer when it turns hotter and drier. Many homeowners think that the lawn is just going through some drought stress and will recover once it is watered. If the stem and crown tissues become infected, large sections of the lawn may be affected and recover is a more involved process that may require lawn renovation.

How to Prevent Leaf Spot From Damaging the Lawn

Although you cannot control the weather, you can make sure to follow good cultural practices to help ensure your lawn continues to grow well.

These cultural practices include:

• Increase mowing height to the highest range for the type of grass growing in your lawn.
• Water deeply, but infrequently, to provide 1 inch of water per week
• Do not water in the late afternoon through the evening hours
• Follow a balanced fertilization program that is best suited to the type of grass growing in your lawn
• Core aerate the lawn every year to promote stronger roots and keep thatch levels in check

There are disease control applications that can be applied and will help some if applied when the damage has already begun, but the best control from these types of applications happens when they are applied before the disease cycle begins in the early spring or fall. Keeping the lawn growing well is the best defense against leaf spot becoming a problem in the lawn.

There is another leaf spot disease, Gray Leaf Spot, that is active during warm, humid periods in the summer.This disease is very active on St. Augustine, perennial ryegrass and turf-type tall fescue. Instead of causing circular lesions, this disease starts out as tiny brown dots, which enlarge to irregularly shaped lesions. When humidity levels are high, the lesions taken on a gray tint, which gives the disease its name. The lesions have a distinct brown border between the healthy and diseased tissue.

If you feel your lawn may be having a problem with one of the leaf spot diseases, contact your local lawn care professional at Spring-Green to have them inspect your lawn!

White or Gray Matted Web-Like Grass? It’s Snow Mold!

Gray Snow Mold

There are two types of Snow Mold that can develop on residential lawns, Pink and Grey. Although all grasses are susceptible to the diseases, they are most common on bluegrass, ryegrass, bentgrass and fescues. Pink Snow Mold, also called Microdochium Patch and Gray Snow Mold, also called Typhula Blight.

Although they are both associated with snow cover, Gray Snow Mold requires at least 60 days of snow cover for it to develop. Both types of Snow Mold are most severe when snow falls on unfrozen turf, but Pink Snow Mold can occur without snow cover during cool (less than 60 degrees) weather that is wet and cloudy.

Identifying Pink and Gray Snow Mold

Gray Snow Mold

Symptoms develop under the snow and become evident as it melts. This lawn disease appears in circular to irregular-shaped patches that can grow as large as 3 feet in diameter. The grass is covered with a white or gray fungal growth and the grass blades appear matted together. In severe cases, large sections of grass blades can be damaged and will take a long time to recover.

Pink Snow Mold

This disease appears in roughly circular-shaped patch that can range from a couple of inches to about a foot in diameter. The disease presents as a white patch with a pinkish ring on the outer border of the patch. The grass blades appear matted and look is if they are glued together. As thee patches dry out, they will feel hard to the touch.

How to Control and Prevent Snow Mold

Both diseases overwinter as spores in the patch layer, so reducing thatch levels is very important. Fall core aerations will help to reduce the thatch levels and improve the health of the turf by developing better root systems and reducing compaction. Avoid excessive nitrogen fertilizer in the late fall and continue mowing if the grass continues to grow. Overly long grass that falls over on itself is more likely to develop snow mold.

If possible, grind up leaves with your mower in the fall to recycle the nutrients back in to the soil. If it becomes too cold to continue mowing, but there are still many leaves on the lawn, do your best to rake them up before the snow starts to fall. Leaves left lying on the lawn provide great conditions for this grass disease to develop.

In most cases, an application of a disease control material is not warranted on residential lawns. Snow mold is usually not severe enough to warrant an application of a disease control material. If small sections of either gray or pink snow mold does develop, lightly break up the fungal mats with a leaf rake or even your fingers if the spots are not very large. If large snow piles remain on the lawn near driveways or sidewalks, do you best to distribute the snow across the lawn so that it melts faster.

Usually this lawn disease is a sign that winter is ending as it is generally seen when temperatures start to warm up and snow quickly melts. If you have any questions or would like us to check it out, don’t hesitate to contact your local Spring-Green. 

Found A Smelly Dark Tip Fungus? It’s Dog Stinkhorn!

dog stinkhorn

Their name doesn’t sound very appetizing, their shape certainly doesn’t help matters much, and their odor can be downright offensive. The genus Mutinus Caninus, also known as Dog Stinkhorn, are a rather unusual garden fungus. This unsavory member of the mushroom family can be recognized by it’s distinctive shape and terrible smell.

What is this dark tip smelly fungus?

They will be hard to miss if you have them. For those not well-versed in Latin, the scientific name describes the similarity of their shape to that of a male dog’s identifying anatomical characteristic. Stinkhorns are generally not considered to be edible and even if you are into mushrooms, you won’t likely confuse these with any of their appetizing relatives, nor will you find them terribly appealing.

Dog Stinkhorn mushrooms are found in the eastern US as well as Europe, Asia, and elsewhere. They usually show up in wooded areas as well as lawns or in mulched beds during the late summer and early fall. Stinkhorns get their name from the spore-rich slime that they produce at the tip. The unpleasant aroma of this slimy substance has been likened to that of decaying animal flesh or of cat droppings. Believe it or not, that nasty odor serves an important purpose: reproduction. Most mushroom varieties reproduce by distributing their spores on the wind.

By comparison, stinkhorns rely on insects to do the job. The same smell that repels people attracts flies and other insects that will land on the slime and feed on it. In the process, they get the spores all over their feet as well as into their digestive system. These insects then take off and spread the spores that they picked up to other areas via natural means. Although this method of distributing spores may not seem terribly appealing to us humans, it is quite effective.

Where Is Dog Stinkhorn Located?

While many stinkhorn fungus varieties are found in wooded areas, the Dog Stinkhorn can also be found among leaves and mulch as well as in rich, cultivated soils such as may be found in your lawn and landscape beds. Dog Stinkhorn mushrooms sprout from an off-white, tough, egg-shaped structure that develops at the ground level or slightly below, often amongst the leaves and mulch and usually out of sight. If you were to look closely enough, you would find that the “eggs” are attached to the soil by white cords called rhizomorphs.

After the bulb erupts, the fungus grows a slender, fragile stalk that can be white, pink or orange in color, with a dark tip that is usually curved and somewhat pointed. This growth can happen rather rapidly, sometimes over a period of several hours, which makes stinkhorns seem to appear from out of nowhere. The good news is that they have a very short life span and will also disappear rapidly.

Even though stinkhorn mushrooms are not considered edible—we certainly do not recommend trying to eat one—they are not poisonous, either. In fact they are very beneficial organisms. Other microorganisms in the soil feed on these, which improves the condition of your soil and ultimately, of you landscape plants. We could not in good conscience tell you to eradicate a beneficial lawn and garden organism. Therefore, there is no prescribed prevention or control for Dog Stinkhorn other than to wait a day or so for them to go away.

While mushrooms are seldom considered a threat to a healthy lawn and landscape, we still encourage you to call on your neighborhood lawn care professional at Spring-Green whenever you have questions or concerns. We are always happy to share our expertise and when necessary, we can diagnose and treat a wide variety of lawn and landscape issues, such as those caused by weeds, pests, and diseases.

Identify and Repair Lawn Disease

Having to repair your grass that has succumbed due to lawn disease can be time consuming and expensive. How the repair is accomplished is different for cool-season grasses than it is for warm-season grasses. This article will provide some basic information for repairing lawn disease.

Regardless of where you live or what type of turfgrass is in your lawn, the most important thing to determine is the name of the lawn disease. Some lawn diseases like Red Thread or Rust will exist for a short time and then the grass will recover on its own. Other lawn diseases such as Large Patch or Summer Patch will kill off large sections of a lawn and may require extensive renovation work.

Understanding why a lawn disease developed will also help in determining the type of repair that should be accomplished. Some lawn diseases develop due to shade, like Powdery Mildew. Others may develop because of too much thatch, like Fairy Ring. If you are not sure what disease is in your lawn, contact a lawn care company, like Spring-Green, to help diagnose the disease and provide the reasons why it may have developed in your lawn.

Lawn Disease Types for Warm-Season Grass

Warm-Season Grass Types:

  • Bermuda Grass
  • St. Augustine Grass
  • Centipede Grass
  • Zoysia Grass

The one major advantage of warm-season grasses is the ability to quickly recover from many of the lawn diseases that may develop due to their above ground roots called stolons. These roots can quickly grow and cover a small to medium-sized area in a short time, typically within 2 to 4 weeks. The major disadvantage of warm-season grasses is that extensive disease damage usually requires resodding the area since it is very difficult to achieve much germination, if any at all, of seed for most warm-season grasses.

One of the major lawn diseases that affects these grasses is called Large Patch. This disease starts to infect the plants in the fall, but the damage is not observed until the following spring. Often, the turf will recover by sending out new stolons to fill in the damage areas, but it often shows up again the following year the damaged areas may increase in size every year. Sometimes the damage will be severe and the area should be resodded.

Proper site preparation is important before installing new sod. This often requires the use of a sod cutter to remove the old, diseased turf, cultivating the soil and leveling the area as necessary. Since Large Patch is a soil-borne disease, applying a disease control material to the soil before installing the sod is recommended.
Sod can be installed at any time of year in the warmer areas of the country, but it is best to install it when the weather is not too hot and not too cold. Late summer to early fall is a good time to repair a lawn with sod, but it is best to have it completed by the end of September.

Lawn Disease Types for Cool-Season Grass

Cool-Season Grass Types:

  • Kentucky Bluegrass
  • Perennial Ryegrass
  • Fine Fescue
  • Tall Fescue

Contrary to warm-season grasses, cool-season grasses can be overseeded to renovate a lawn damaged by disease. The easiest way to incorporate new seed in a cool-season turfgrass lawn is to core aerate it first and then spread seed across the lawn. The best time to do this is late summer into early fall.

Some of the worse lawn diseases on Kentucky Bluegrass are the Patch Diseases – Necrotic Ring Spot and Summer Patch. These are also soil-borne diseases and thee fungi remain in the soil. If all the diseased sod is removed and replaced with new sod, the disease will most likely return within a few years. Seeding is the better option when helping a lawn recover from these diseases.

Once again, before going to the expense of repairing a lawn due to disease activity, be sure to properly identify the disease and the reason why it developed. It may require less work to correct the problem.

If you feel your lawn has suffered from a disease, contact your neighborhood lawn care professional at Spring-Green and have your lawn evaluated and put together a plan to help it improve.

How Rust Lawn Disease Develops and Ways to Prevent It

rust lawn disease

If you have ever walked across your lawn in the late summer and notice that your shoes have taken on an orange hue, there is a good chance that your lawn is suffering from a common turf disease called Rust. The lawn disease appears as orange or yellowish-orange powder on grass blades, usually in the late summer to early fall, although I have seen in develop in the spring.

How Does Rust Develops On Lawns?

The disease can develop on turf that is not growing normally due to several stress factors including drought stress or low fertility. It can also develop during periods of heavy rain fall. Cool nights with heavy dew is another environmental condition that can favor its development. On the other hand, warm, cloudy and humid weather followed by hot, sunny weather can also lead to its development. In other words, just about any type of weather we can get in August can benefit the development of Rust.

The grass species that are most prone to develop Rust include Perennial Ryegrass, Tall Fescue, Kentucky Bluegrass, Zoysia Grass and St. Augustine Grass. Not all cultivars of these grasses are prone to Rust, which is a good idea to check for the cultivars that are less susceptible by searching the NTEP or National Turfgrass Evaluation Program by going to www.ntep.org. Some of the data may seem too technical, but if you scroll through the various reports, you will find a list of the species and cultivars that were tested, where they were tested and the quality ratings of each cultivar.

Rust starts off as small. Yellow flecks on the grass blades and stems. Over time, these flecks grow and expand into raised pustules that are also orange or yellow in color. Once the pustules reach maturity, they will rupture and spread a powdery mass of spores across the turf along with your shoes, pants, lawn mower, dog, etc. In heavily infected areas, the turf can thin out and clouds of rust spores will rise as the turf is disturbed. Once all the spores are released, the pustules will turn black. The spores that are left behind are present to re-infect the turf once the optimal environmental conditions return.

Preventing Rust On Your Lawn

You can reduce the likelihood of the disease developing again by following good cultural practices for proper mowing, watering and fertilizing for the type of turf that is in your lawn.

Proper watering is one of the more critical cultural practices to help prevent outbreaks of Rust. Water deeply, but infrequently to encourage roots to grow deep. Allow the turf to dry out between watering and avoid watering in the evening hours.

There are disease control materials that can be applied as a preventative, but once the pustules form, it is too late to control the disease as it is at the end of its life cycle. Often, an application of fertilizer with nitrogen will stimulate new growth and help the lawn recover from the effects of the disease.

If you see that your shoes are turning orange after walking on your lawn, contact your local lawn care professional at Spring-Green to have your lawn checked for Rust. Spring-Green will develop a program that combat the effects of Rust.

If You Had a Dollar for Every Dollar Spot On Your Lawn…

Dollar Spot Lawn Disease

You probably wouldn’t be rich, but you might have enough for a decent night out. We’re speaking, of course, about Dollar Spot, the lawn disease that cheapens the look of your lawn. This lawn disease can infect almost all cool-season and warm-season turfgrasses, including Bentgrass, Fescues, Kentucky bluegrass, Perennial Ryegrass, Bermudagrass, Zoysiagrass, Centipedegrass and St. Augustinegrass.

Development of Dollar Spot Lawn Disease

If conditions are right, the disease can develop on most any lawn, but a well-maintained lawn will recover from the damage faster than a lawn that does not receive the proper cultural practices for mowing, watering, fertilization and thatch control.

The conditions for Dollar Spot development include:

• Air temperatures from 60-90°F (most active at 70-80°F)
• Extended periods of high humidity, especially at night
• Most damage occurs when days are warm, nights are cool and dew is present for more than 8 hours
• Lawns that have low nitrogen fertility levels

Symptoms of Dollar Spots start with the development of fungal growths called mycelium, which invade the grass blades. On low cut grasses like bentgrass or Bermudagrass, the mycelium will form small, silver dollar sized spots, which is where it gets its name – Dollar Spot. On higher cut grasses, the patches are larger and can merge to form large blighted areas of turf.

The mycelium forms early in the morning and will often dry out as the sun rises in the morning. It will leave behind a definitive hourglass-shaped lesion on the grass blade that has a reddish brown border. In some cases, the leaf blade will turn a tannish-white color from the tip down, but it almost always has the reddish brown border between the damaged part of the leaf tip and the remaining green part of the blade.

Prevention and Treatment for Dollar Spot

Treating Dollar Spot requires following proper cultural practices. At Spring-Green, we develop a partnership with our customers. We rely on them to water during the morning hours and to water deeply, but infrequently. Mowing is also critical in preventing Dollar Spot development. Every turfgrass has a range of heights at which to mow.

During the late spring and summer months, mow at the highest recommended height for the turfgrass in your lawn. Another important practice is to core aerate your lawn every year. Core aeration will help improve root growth, which leads to a stronger lawn.

By following Spring-Green’s Preferred Lawn Care Program, your lawn will receive the proper amount of nutrients to develop a healthy lawn that can resist or recover from disease pressures. There are disease control materials available to help prevent Dollar Spot from developing and Spring-Green can apply those treatments if the disease is observed early on.

In most cases, a healthy, Spring-Green lawn will survive and recover from a minor disease infestation. Contact your neighborhood lawn care professional at Spring-Green to help prevent Dollar Spot from developing on your lawn and landscape.

How Do Lawn Diseases Develop and Ways to Prevent Them

lawn disease

If there is a disease that can develop where you live, the spores of that disease are probably in your lawn already as they will move from lawn to lawn mainly through wind movement. Some diseases are soil borne, meaning that they already exist in the soil. All diseases are waiting for the right environmental conditions to develop to infect the turf.

Development of Lawn Disease

It is important to understand how a disease develops. The term used to explain how a disease develops is called the Disease Triangle. It is basically the same concept as the Fire Triangle. There are three basic components that are required for a fire to develop – fuel, heat and oxygen. If one of the three is removed, the fire is extinguished. In the Disease Triangle, the three components are host plant, pathogen and environment.

In regards to lawns, the host plant is the turfgrass in your lawn. The pathogen, as was mentioned earlier, already exists in the lawn as a dormant spore. Think of a spore as a tiny seed, waiting for the right conditions to begin its development. These spores can be fungi, bacteria or viruses. The right conditions is the environment that favors its development.

There are diseases that develop in cool weather, warm weather and hot weather. A critical component is moisture. Too much water or high humidity generally favors more disease development. Along with weather, the environment includes the growing conditions for the turfgrass. Soil pH and fertility can lead to an unhealthy plant, which can be more easily colonized by a disease. Lawns that are mowed too short will result in a weaker plant and more susceptible to disease development. Too much or too little fertilizer can also lead to disease development.

Preventing Lawn Disease

The amount of thatch that has developed in a lawn can also lead to disease development as thatch can act like an incubation chamber for many diseases. The best way to inhibit the development of a disease in your lawn is to follow proper cultural practices of mowing high, based on your turf species, watering deeply, but infrequently, core aerate the lawn once a year and follow a proper nutritional program to ensure the health of your lawn. Of these practices, the most important one is mowing.

Here are the recommended mowing heights for the most common turfgrasses:

• Bermuda Grass 1/2 to 1-1/2”
• Zoysia Grass 3/4 to 1-1/2”
• Centipede Grass 1-1/2 to 2”
• St Augustine Grass 3-1/2 to 4”
• Tall Fescue Grass 3 to 4”
• Bluegrass 2 to 3”
• Perennial Ryegrass 2 to 3”
• Fine Fescue 2-1⁄2 to 3-1⁄2”

Proper watering is also very important. Many people with an automatic sprinkler system water too much. Reduce the number of days you water and invest in a rain sensor so the system doesn’t run while it’s raining or if rain fall has been plentiful. Training a lawn to be more water efficient starts with reducing the frequency of watering, but increasing the length of time each zone is watered based on sprinkler head type and size of the area being watered.

sprinkler system
 

There are disease control materials available to treat most diseases, but the control is usually temporary and the disease often comes back. That is why Spring-Green recommends improving the growing conditions as the best approach to preventing diseases from developing in your lawn. There are some situations where, due to intense environmental stresses, a disease control program may be the best choice. Contact your neighborhood lawn care professional to determine the best approach to reduce disease development in your lawn.

How To Control And Treat Red Thread Lawn Disease

red thread lawn disease

One of the more common late spring to early summer diseases on cool-season grasses is Red Thread lawn disease. It is most severe on Kentucky Bluegrass, Perennial Ryegrass and Tall Fescue. There is another lawn disease that occurs at the same time and under the same environmental conditions known as Pink Patch.

The main difference between the two lawn diseases are the fruiting structures. Red Thread takes its name from the red thread-like structures called sclerotia that are produced by the fungus. Pink Patch produces tiny puffs of pink-cottony mycelium that resemble little bits of cotton candy stuck to the grass blades. Of the two diseases, Red Thread is the more common one seen in home lawns. Red Thread may develop when temperatures range from 40 to 75°F. Most grass activity occurs when temperatures range 65 to 75°F and during periods of cool, cloudy weather with long periods of evening dew.

What Does Red Thread Lawn Disease Look Like?

Symptoms are often visible from the street as circular patches of tan or pink grass about 4-8 inches in diameter. Upon closer inspection, the sclerotia are easily visible, appearing like small, red threads protruding out of the grass blades, especially near the tip. Red Thread will affect the leaves, leaf sheaths and stems without killing the entire plant, unless the outbreak is severe. The infection begins as small blighted areas on leaves and rapidly enlarge, covering the entire leaf blade. The affected leaves will dry out and turn a bleached straw color.

After it has completed its life cycle, the disease produces the red threads or sclerotia. In other words, unless the weather conditions last a long time, the red threads signal the end of its activity. These threads will break off and act as “seeds” for future outbreaks of the disease. Mowing infected areas has little impact on spreading the disease so collecting clippings during this period is not very beneficial.

How To Treat Red Thread Lawn Disease

It is important to maintain an adequate nitrogen fertility program to lessen the effects of Red Thread. Fertilization after an outbreak of Red Thread will help the turf to “grow out” of the effects of the disease activity. Fertilizer will help the lawn grow and then the diseased parts of the plant can be mowed off to allow newer, healthy blades to grow. Avoid excessive watering during cool, cloudy periods that may extend the time the turf remains wet. Core aeration and overseeding with improved varieties of turf grasses that are more resistant to Red Thread are another two important cultural practices.

There are chemical control options, but by the time the red threads are seen, it is usually too late to apply a preventative disease control application. Making sure the lawn is well fertilized, mowed properly and receives the right amount of water on a weekly basis is the best approach to take when dealing with Red Thread lawn disease.

If Red Thread is a problem in your lawn, contact your neighborhood lawn care professional at Spring-Green. They will be happy to inspect your yard and provide a beneficial lawn care program.

Early Spring Start-Up Tips

early spring off to a great start

Spring is just beginning for those in the northern states. Many gardeners are getting anxious to shake off the winter doldrums and start working on their lawns, landscape beds and gardens again.

After being teased by Mother Nature in mid to late February with warm temperatures, the last month or so has been cold, snowy, wet and just down right miserable. During those few couple of warm days the grass began turning green, Tulips and Daffodils pushed through the soil and buds on the trees and shrubs were getting ready to open.

One thing to keep in mind; it is only the middle of April and the chance for temperatures to drop below freezing is still a real possibility. In fact, for much of the northern US, the chance for frost can persist until at least Mother’s Day.

5 checklist items for early spring start-up:

day lily from damage

  1. Walk and survey – I know that I plan to walk around my lawn this weekend to see what did and didn’t survive through winter. I do know that my Day Lilies and Irises all have white tips due to the bitter cold temperatures. These plants will survive just fine and the white tips will eventually turn brown. They may look a little ragged for a few weeks, but they are hardy plants and have adapted to the cold weather. It is still a good idea to take a walk around your lawn on a warm sunny day to see how things fared during the winter months.
  2. Compost – If you are in the mood to do some work around your yard, rake up the leaves that have inevitably blown in during the winter. There have been some fairly significant wind storms in March and early April, so picking up dead branches will also be an early outdoor task. Put the leaves and branches in your compost bin, although you may have to cut up the branches into smaller pieces unless they are of significant size then they can always be used for firewood.
  3. Scan for disease – Check for possible disease activity, such as Snow Mold. Look for patches of matted grass that appear to be glued together. It is easy to “cure” your lawn from Snow Mold damage by using your fingers in a raking fashion to break up the matted grass. In some cases, large sections of a lawn can be affected, so using a flexible-tine rake is the best option. Lightly rake the spots to break up the matted grass to allow new grass to grow back and fill in the matted patches.
  4. Fertilize – Applying a spring fertilization is another important task. When cool-season grasses come out of winter dormancy, the end for food is important. Don’t worry if it rains or even snows after your lawn has been fertilized. Any type of fertilizer, whether applied as a liquid or granular, needs water to wash it into the spoil where it can be taken up by the roots.
  5. Time your planting – It is still early, although I have seen some garden centers already displaying “cool weather” plants like Pansies and Violas. In most cases, there are still another 3 to 4 weeks before annual plants can be planted. Some garden plants can be planted early, such as lettuce, or if you are using cold frames to start vegetable plants. The ground is still wet and it has to dry out before tilling the soil. In the meantime, draw up some plans of where you want to plant, search the Internet for different flowers and landscape ideas. There is plenty of time before you get out the shovels and rakes.

If you have questions about problem areas in your lawn this spring be sure to contact your local neighborhood lawn care team at Spring-Green.

Slime Molds: Should You Be Concerned?

slime molds growing on a lawn

Many parts of the country are dealing with hot, humid weather and an abundance of rain. This type of weather is conducive to the development of a disease called slime molds that causes a great deal of concern, but is really nothing to worry about.

They can occur anytime from spring through fall, but seem to be more active following heavy rains in the summer. They can develop on any grass plants, including grassy weeds.

Slime molds are saprophytes, or primitive organisms that obtain their nutrients from dead or decaying organic matter. They use the grass blades for support for their spore production and do not directly affect the plant. The organism produces small fruiting bodies on the leaf surface that grow out perpendicular from the blades.

These fruiting bodies start out about the size of a pin head, but grow larger as more spores are produced and are now more noticeable. The fruiting bodies range in color from dark blue, to purple to gray. They can develop in patches from a couple inches to several feet wide. When touched, the spores can send out a small “puff” of spores, which can cause concern to many homeowners who happen upon these unusual patches.

slime mold growing on a lawn

What do you do when you find Slime Molds growing in your lawn?

Let nature take its course, action is not necessary. The fruiting bodies will dry out and fall off the grass blades. Normal mowing will also dislodge many of these fruiting bodies as well. If it is a cause of anxiety, you can take a hose and wash them off or use a broom and sweep them off the grass blades.

Remember, the spores from this year’s growth will end up in the thatch and could develop again the following year in the same location. If you think about it, it is a good thing as it is a sign that your lawn has plenty of microbial activity feeding away at your thatch layer.

If you have concerns about slime mold growing on your lawn, contact your local Spring-Green for more information.