What It Is, Why It Happens, and How to Manage It
Dollar spot is one of the most common lawn diseases we see in Minnesota during the summer months. It often appears after periods of warm days, cool nights, and heavy morning dew. Homeowners are frequently surprised when their lawn develops hundreds of small brown spots seemingly overnight.
The good news is that dollar spot is primarily a cosmetic disease. While it can make a lawn look unhealthy, it rarely kills the grass. In most cases, the grass plants remain alive and can recover with proper care and favorable growing conditions.
How to Identify Dollar Spot
Dollar spot is fairly distinctive once you know what to look for.
Early Symptoms of Dollar Spot
The first signs are small, circular patches of straw colored grass scattered throughout the lawn. Individual spots are usually about the size of a silver dollar, giving the disease its name, although they may range from 2 to 6 inches across.
As the disease progresses, hundreds of these spots can develop across the lawn. In severe cases, the spots begin to merge together, creating larger irregular brown areas.
Looking at Individual Grass Blades
Pull a few blades from the edge of an affected spot and inspect them closely.
Grass infected with dollar spot often has:
- Tan or bleached lesions across the leaf blade
- Hourglass shaped lesions
- Dark brown or reddish borders around the lesions
During cool, humid mornings, you may also notice a white, cottony fungal growth on the grass.
Why Does Dollar Spot Happen?
The fungus that causes Dollar Spot exists naturally in most soils. Therefore, the disease is often waiting for the right environmental conditions. Dollar spot thrives during periods of
- Warm days
- Cool nights
- Heavy morning dew
- High humidity
Stressed grass from heat and lack of water can increase how much and how quickly Dollar Spot develops.
Common Misconceptions
“My lawn is dying.”
Fortunately, this is rarely the case. Dollar spot usually damages only the leaf blades. The crown and root system typically remain healthy, allowing the grass to recover.
“I watered too much.”
Not necessarily. The fungus actually relies heavily on prolonged morning dew. Proper irrigation is still important. Watering deeply in the early morning is much better than frequent, shallow watering or watering late in the evening.
“The lawn company caused the disease.”
No. Dollar spot develops because environmental conditions become favorable for disease. Even well maintained lawns can develop dollar spot during humid weather. Proper fertilization and good cultural practices reduce the severity but cannot eliminate all disease risk.
“I need to reseed.”
Usually not. Most lawns recover naturally as healthy new leaf blades grow and replace the damaged tissue.
What Can You Do Now That You Have Dollar Spot?
The focus should be on helping the lawn recover while reducing conditions that favor the disease.
- Water Properly – Water deeply and infrequently, preferably early in the morning. This allows the grass to dry quickly during the day while encouraging deeper root growth.
- Continue Mowing – Continue mowing as needed while following the one third rule. Sharp mower blades help minimize additional stress.
- Reduce Lawn Stress – Avoid unnecessary stress during hot weather. Heavy foot traffic, drought stress, and scalping can all slow recovery.
- Improve Airflow – If practical, prune trees or shrubs that block sunlight and air movement. Faster drying grass reduces disease activity.
- Be Patient – Recovery often occurs within a few weeks once growing conditions improve. The lawn simply needs time to grow new leaf blades.
What Can bioLawn Do Now That You Have Dollar Spot?
Our agronomy team begins by confirming that dollar spot is actually the problem. Several lawn diseases, along with drought stress and heat stress, can look very similar.
Once identified, we can recommend the most appropriate course of action based on the severity of the disease.
Depending on the situation, we may recommend:
- Adjusting your fertility program to encourage healthy growth
- Improving watering and mowing practices
- Monitoring recovery over the next few weeks
- Applying a fungicide if disease pressure is severe or continues to spread
In many cases, improving growing conditions is all that is needed for the lawn to recover.
What Can You Do to Prevent Dollar Spot?
The healthiest lawns are the least likely to experience severe outbreaks.
- Water Correctly – Water deeply and early in the morning rather than applying frequent, shallow irrigation.
- Mow Properly – Keep your mower blade sharp and avoid removing more than one third of the grass blade at a time.
- Reduce Thatch – Core aeration and healthy soil management help reduce excessive thatch that can hold moisture.
- Improve Air Circulation – Increasing sunlight and airflow helps morning dew dry more quickly.
- Reduce Other Stress – Healthy, actively growing turf has a much greater ability to resist disease than stressed grass.
What Can bioLawn Do to Help Prevent Dollar Spot?
Preventing dollar spot starts with building a healthier lawn that is better equipped to tolerate disease pressure.
Our bioBase Lawn Program includes the necessary fertility to support active lawn growth. However, if dollar spot is a concern, we recommend our bioBoost or bioBest Lawn Packages.
Our bioBoost and bioBest Lawn Programs include soil and plant health additives that build natural tolerance and protection against dollar spot disease. Thereby, we see less dollar spot disease in lawns treated with the bioBoost and bioBest Lawn Programs.
Because weather plays such a significant role in disease development, no lawn care program can completely prevent dollar spot every year. However, maintaining healthy, vigorous turf is the best way to minimize outbreaks and help your lawn recover more quickly.
If you’re unsure whether your lawn has dollar spot or another issue, send our agronomy team a few photos. We’re happy to help identify the problem and recommend the best next steps.