What Is Dollar Spot- Dollar spot is a turf disease primarily caused by the fungus Sclerotinia homoeocarpa.
This disease is most common with high-maintenance turfgrasses like those found on golf courses or sports fields, however, it’s not uncommon for it to be spotted in residential lawns.
It is becoming a more serious concern for lawn owners because of the extension of this disease in the country. The disease can weaken the roots and the quality of the grass internally, making it harder for the grass to survive in the fall.
Let’s start with a basic look at the appearance and description of a dollar spot. This description will make identifying the problem much easier.
How’s The Dollar Stain
Dollar Spot includes small round, whitewashed spots on lawns, ranging from 5 to 6 inches on home lawns. The disease also changes the color of the grass to a straw-like tan, affecting its natural appearance and luster.
You can find these dollar spots on a variety of grasses. There are a few symptoms of dollar spots that owners should be aware of.
1. Size
There is no set size for dollar patches on your lawn, but they are closer to the dime size in most cases, as the name suggests. As mentioned above, the typical size of dollar spot damaged areas on your lawn is usually 5 to 6 inches.
However, this can be higher depending on the turf conditions.
2. Location Of The Leaves
The leaf blades of the leaves affected by the disease usually have an erect appearance that is white or pale. The lesions change color with red-brown borders.
3. Dying Leaves
Leaf tips begin to die off at the surface after girdling, which is the clearest indicator of dollar spot in turfgrasses. However, this may not be seen on closely mowed lawns.
Instead, the leaves may turn white or brown at the tips. In these places, the grass begins to die back until it spreads across the entire lawn.
Some homeowners may also see a short, flaky mycelium forming on the lawn. This increases when morning dew is present and begins to contribute to the disease.
Brown Spot Vs. Dollar Spot
Some people often confuse brown spot with dollar spot and vice versa. However, both differ in their respective solutions.
Although both diseases are caused by an invasive fungus, their conditions are different. For instance, brown patch, or Rhizoctonia solani, includes brownish-yellow “patches” that can spread through the surface of turfgrass if not controlled properly.
Brown patches may start at a few inches (usually around 6 inches) but can spread as much as several feet if you do not take steps to treat them. Brown patch becomes more severe during warmer weather in the U.Similarly, high humidity levels can also cause this disease to escalate.
The dollar spot has smaller spots on the ground. Similarly, these patches of grass are perfectly circular, distinguishing them from a patch of brown.
However, understanding the difference between the two can be a bit difficult for some owners. The best way to identify any type of illness is to send a sample to your local counseling service office and see what your symptoms look like.
However, some factors influence the development of the disease.
Weather Conditions
The main cause of dollar stains is a change in weather conditions and consequently the soil conditions in your lawn. Infestations are much higher in the spring season compared to other times of the year.
However, the temperatures have to overcome a special barrier for this to happen.
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Temperature
Temperature is a key factor in the development of dollar spots on lawns. Dollar spot growth increases at higher temperatures. While exact temperatures will vary, a temperature range greater than 50°F is a must.
Leaf Wetness As mentioned in our lawn disease control article, dollar spot disease also requires a certain level of moisture for the pathogen to spread. This period ranges from 10 to 12 hours of constant leaf wetness in most cases.
In combination with cool nights, periods of excessive humidity can certainly contribute to dollar spot breakouts.
Nutritional Deficiencies
The type of nutrition grasses receive affects the overall strength and resistance to dollar spot for most lawn grasses. Lawn grasses with lower potassium levels generally have poor dollar spot tolerance and are easily infected.
Drought Stress
Drought conditions negatively affect the lawn, which can also increase the growth of dollar spots in a lawn. In other words, turf grasses that have been weakened by another external stressor generally become more susceptible to disease outbreaks.
Excessive Thatch and Overwatering
Extra thatch growth and overwatering can make it difficult for the lawn to stay healthy. Both of these factors block the lawn’s ability to absorb nutrients and contribute to lawn diseases such as dollar spot.
Conduct a watering check to ensure your lawn is getting the right amount of water.
When Does Dollar Spot Appear On Lawns
Dollar Spot grasses typically attack in the spring when nighttime temperatures exceed 50°F, although disease symptoms may not appear until later in spring or early summer.
What Types Of Grasses Are Affected By Dollar Spot
You can find dollar spots on a variety of grasses. shorter height. The dollar spot is 5 to 6 inches in diameter depending on the severity of the disease on grasses maintained less than 1 inch tall.
You can also find dollar spots in taller grasses (like most lawns). Some grass species may be at a higher risk of developing dollar spots. For example, bent grass, perennial ryegrass, Kentucky bluegrass, and Bermuda grass are the most common grass species for dollar-spotted shoots.
Treatment
The following are some common preventive measures and treatment options that homeowners should consider when caring for their lawns.
1. Cultural Control
Avoid cutting grass too short: Shorter grass has a higher risk of contracting dollar spot disease. Don’t cut the grass too thin. Learn more about the ideal cutting height for your type of grass here. Avoid cutting grass under 1 inch.
2. Water The Lawn in a Timely
Watering patterns in your lawn affect the spread and growth of lawn pathogens. Therefore, avoid overwatering the lawn as this can lead to more fungal growth. Consider conducting an irrigation audit.
3. Keep Your Lawn Clean
The growth and accumulation of thatch can prevent needed nutrients from reaching the soil. So make sure to keep your lawn clean and maximize aeration in the lawn for better growth and driveability.
4. Add Fertilizer
You now understand how malnutrition affects the dollar spot. So try using a fertilizer with more potassium to keep your soil free of hump stains.
5. Use Soil Test Results
You can always do soil tests if you’re not sure what’s wrong with your lawn. These tests provide a comprehensive report and help lawn owners determine the best course of action to solve the problem at hand.
Chemical Dollar Stain Control
If dollar stains have already appeared on your lawn, the next step is finding the right treatment. Although dollar spot fungicide application can be a little tricky, it is effective in controlling the disease in your lawn.
What Is The Best Dollar Spot Fungicide
There are many options to consider when looking for the best dollar spot disease control. For best results, you can use chlorothalonil, fluoxastrobin, or azoxystrobin to control dollar stains in your lawn.
These fungicides are available under brands such as Liquid Ornamental and Vegetable, Fame, and Heritage by Southern Ag. Armada 50 WDG is also an effective dollar spot disease control product.
How Do I Avoid Dollar Stains
While disease control products are typically used to correct diseases like dollar spots in your lawn, they can also be used to prevent diseases in the first place. Consider rotating fungicides with different active ingredients to prevent this.
Because applications vary by grass type, it’s important to follow label directions carefully. Fungicide applications are typically made at 14 to 28-day intervals, although the season for application may differ between cool-season and warm-season turf grasses.
How Does Dollar Spot Lawn Fungus Thrive
Dollar Spot thrives in dry soil conditions and moist air. When the roots are starved of water and the blades of your lawn are wet from dew, rain, or irrigation, the shoots on that lawn will increase in disease.
This lawn fungus is at its worst during summer and seasons characterized by high humidity, little rain, and temperatures between 60 and 80 degrees Fahrenheit. According to the Penn State College of Agricultural Sciences, the fungus is spread through the mycelium to infected plant parts (mainly clippings).
Mycelium can also be carried by the wind, water, or on lawn equipment and shoes.
Disease Cycle
Occasionally the pathogen forms apothecia, but they are sterile. No sex spores have yet been discovered in North America. The spread of the pathogen is limited to movements of infected leaf debris via equipment, people, animals, wind, or water.
When environmental conditions become favorable for pathogen activity (warm, humid, high canopy humidity), dormant mycelia and stromata in infected debris resume growth in plant tissues. If there is sufficient moisture in the sod canopy, the mycelium can begin to invade new leaves and the new host, causing infection.
Late Fall. Temperatures for the spot dollar range from 15 to 30°C (59 to 86°F); different biotypes of the pathogen become infected at different temperatures. Dew formation, driven by warm temperatures and high humidity during the day followed by cool nights, promotes disease development.
Dollar spot is most severe on dry soils, but the disease requires high moisture in the lawn canopy to thrive. Low nitrogen fertility may increase susceptibility to Turfgrass Dollar Spot.
Nitrogen stress can contribute to the severity of the disease, as plants lacking nitrogen are more likely to develop weakened senescent leaves that are more susceptible to infection than plants with sufficient N levels.[2]
Frequently Asked Questions
Is Dollar Spot Caused By Nitrogen Deficiency?
Nitrogen-deficient grass tends to develop more dollar spots than properly fertilized grass. Apply the recommended amounts of nitrogen and ensure adequate air circulation. Keep the grass to a minimum.
How Does The Dollar Spot Spread?
Dollar spot easily spreads to leaf tissue or clippings from infected areas. Avoid spreading the disease by washing equipment before entering an uninfected area and by removing and discarding clippings from infected areas.
Is Dollar Spot A Leaf Disease?
The common foliar disease is found in most grass species (bent grass, Bermuda grass, bluegrass, buffalo grass, fescue, ryegrass, and zoysia grass) throughout Oklahoma.
What Is The Difference Between Dollar Spot and Brown Spot?
The brown spot is a lawn fungus that usually starts as a small brown spot and then spreads quickly. Dollar spot, most common in early summer, is another type of lawn fungus that spreads quickly. grass leaves are most likely infected by a lawn disease known as rust.
How Are Brown Spots On A Dollar Spot Treated?
Solution. To treat Dollar Spot, use Richgro Mancozeb. Apply 10 liters of spray per 10 square meters. Repeat every 10 days during disease-prone periods.
What Causes Fungus In The Lawn?
Excessive heat and humidity are the main causes of fungus. As mentioned above, fungi often appear during times of stress such as drought, long rainy seasons, and excessive watering. The fungus often develops because water remains on the leaf surface for too long.
Final Thoughts
If your lawn suffers from dollar spot, ignoring the problem will not help your lawn fight this lawn disease. All it takes is a little TLC to get your lawn healthy again and control the dollar spot.
If Dollar Spot infests your lawn, hire a local lawn man to treat the lawn disease for you. Better yet, hire a professional lawn care professional year-round so you never have to worry about lawn care again. Your garden will thank you.
