Dollar Spot is a disease that causes spots of pale, light brown grass in an otherwise healthy lawn. The name comes from the fact that the spots are usually roughly the size of a US one dollar coin (similar in size to a British two pound coin). Despite the name, the disease is also relatively common in the UK. If left untreated, the spots will tend to multiply and join together to form larger areas of discolouration.
PHOTO BY Scot Nelson / CC BY
Identification
There can be numerous reasons why a lawn might show small patches of discolouration, but there are several things to look out for that can help you identify Dollar Spot. The disease is caused by the fungus Sclerotinia homoeocarpa and you may spot strands of white mould resembling cobwebs around the affected grass, especially on mornings where the grass is covered in dew.
Looking closely at your grass, you may be able to spot light coloured patches surrounded by red-brown outlines in the grass at the edges of the affected areas. The discoloured patches may also have sunk slightly below the level of the surrounding grass.
Causes of Dollar Spot
Dollar Spot is most commonly found on grass with a high content of fescue species that has been cut very short. The fungus is encouraged to release spores and spread by humid conditions, so is most common when the weather is warm and wet. It will not usually gain a hold on a well-fertilised lawn as the fungus thrives in less fertile soil and grass that is not well nourished will have a harder time fighting off the disease.
PHOTO BY Scot Nelson / CC BY
Treatment
If Dollar Spot is already blighting your lawn, you may need to resort to a chemical fungicide to get rid of it. However, there are several steps you can take to make Dollar Spot less likely and prevent it from spreading if it is already in your grass.
The first step is to prevent moisture lingering on the surface of your lawn for too long, making conditions less ideal for the fungus to grow. Make sure to aerate your lawn regularly as this allows water to drain off the surface and make its way down to the roots where it is needed.
Make sure to regularly feed your lawn with high quality lawn fertiliser, providing the ideal growing conditions for your grass and less attractive conditions for Dollar Spot. This will also make your grass generally more robust, helping to prevent a whole host of diseases.
If you have been cutting your grass very short, raise the cutting height at least temporarily to allow the grass a chance to recover.
The team here at Proctors are always happy to offer advice on the best way to deal with any issues you are having with your grass. Simply call 0117 311 1217 with your query or Ask John.
