Fortunately Dollar Spot Disease is quite easily treated - and prevented. It is mainly a disease wrongly associated with Fescue Grasses which are added to most lawn grass mixtures and turf mixtures these days. However, most grasses used in sports and other intensely maintained turf are also susceptible to the disease.
Dollar spot is normally the problem of the fine turf sports managers - such as bowling green and golf course greens. This is mainly because of the grass maintenance regime, and also because of the high level feeding and watering generally carried out.
There is an increasing tendency for grass seed suppliers to include Creeping Red Fescue in many of their mixtures, so Dollar Spot Disease could well become a little more common than in past. I noted recently that out of seven lawn mixtures available on a garden centre shelf, five contained Creeping Red Fescue. As above, most other grasses are capable of being hit.
Dollar spot disease in lawns is not the most common of diseases - but is often mistakenly identified as Fairy Rings and Fusarium Patch disease.
It is more of a problem in the USA - rather than the UK, but that does not signal that there should not be an awareness. If you are in an area that is prone to dollar spot, then it can be one of the most troublesome of fine turf diseases.
It does not normally cause a problem with utility grade turfed lawns, though again, Creeping Red Fescue is increasingly added to even the most basic Ryegrass turf mixes.
Dollar Spot - Sclerotina etc - is usually prevalent in dewy periods. Spring and Autumn being the most troublesome times for this lawn disease.
Dollar Spot disease starts as small circular patches of dead grass - usually around a couple of inches across. On neglected grass that is not regularly cut, these spots may show up with larger spots in the turf. Sometimes in early morning dew, a white fungus growth can be visibly in the spots.
The spots can spread in an untreated lawn, so treatment with a Carbendazim spray (Carbendazim is a fungicide but when used on turf to control Dollar Spot disease, it causes worms to be deterred from entering treated soil and in 2017/18 it has been banned in the EU and USA. ) quite early in the outbreak, is important. Spreading of the fungal disease is normally as a result of traffic movement - either human feet or mechanical such as mowers and other lawn care machinery.
Since 2018 gardeners are having successful control with 'Provanto Lawn Disease Control' or 'Lawn Disease Control'
Again, a good lawn maintenance and care regime is quite important, together with brushing early dews off the grass in affected areas. Awareness of the effects of over-feeding and over-watering in particular are the first remedies towards preventing dollar spot on fine lawns. Damp climatic conditions - spring and early autumn are often the main times of infection.
Good drainage and removal of surface water by brushing the turf, is one of the best ways to prevent this disease. Such close attention also enables the disease to be found in its early stages.
Removal of Thatch, as a part of your maintenance schedule will do much to prevent the Dollar Spot Disease. The main reason for this - as a preventative method - is because the disease normally overwinters on plant debris and decaying od dead plant tissue - ie Thatch! It can also overwinter in areas of rough grass waiting to be transferred by traffic in the spring.
As well as removing the potential winter 'hideaway' thatch removal will assist in keeping the turf free from surplus water and moisture - allowing dew and the like to dry off more quickly.