Identification: As with many lawn diseases, when dollar spot first begins, it can appear as a water-soaked and/or wilted area in the lawn before the affected area changes color. If your lawn is fine textured or close-cut, then Dollar Spot often appears as brown, round, sunken spots roughly the size of a silver dollar, which is where it derives its name. If you have a lawn with a more coarse textured grass or maintain a higher cutting height, then the brown spots tend to be larger and more diffuse. In these situations, it is easy to mistake Dollar Spot with Brownpatch. An easy way to tell the difference between these two diseases is to take a close look at the leaf blades of the grass in question. With this disease, lesions appear on living grass leaves near the infected area. These lesions are light tan with a reddish-brown border and tend to radiate from the margins of the leaf. In some cases, the lesions can actually girdle the leaf-blade.
Cause: This disease is most active when temperatures in the day are around 70-85 degrees and, in the night, around 60 degrees. Thus, the most likely times for this disease to affect your lawn is during the spring, early summer, or fall months. Low amounts of moisture can contribute to disease activity, as can low nitrogen and potassium levels. When there is an infected area, it's also important to remember that this disease can very easily be spread from one place to another by water, lawn mower clippings, and even shoes.
Prevention:
- Remove excess thatch
- Fertilize when necissary to maintain adequate fertility levels
- Water thouroghly and infrequently
- Maintain your lawn at its recommended mowing height
- Aerate your lawn regularly
- Apply preventative fungicides if this disease is likely to affect your area
- Water in the morning rather than later in the day
Treatment: While Dollar Spot can be damaging to your lawn, in most cases, it is fairly easy to help your grass recover. My fertilizing properly and generally working to create a healthy lawn, diseased areas can usually re-grow. It can also help to apply fungicides which are specifically labeled to deal with this problem. If you have had troubles with this disease in the past, it is usually advisable to apply a fungicide to deal with Dollar Spot before any symptoms occur, either in the early spring or fall.
Susceptible Grass Types
- Bermuda Grass
- Fescue
- Ryegrass
- Bluegrass
- Zoysia Grass
- Bentgrass
- Centipede Grass
