Home ▸ Lawn Care Guide ▸ Lawn Disease ▸ Dollar Spot

Dollar Spot

What is it?

Dollar spot is another lawn disease caused by fungus and causes small, silver dollar-sized patches of brown-yellow grass (hence the name). On close inspection of infected grass blades, you will see pale lesions with red-brown edges, some of which may be small spots, but others may be large, elongated and covering nearly the entire grass leaf. Bent and fescue grasses are particularly vulnerable, so this disease used to mainly affect golf and bowling greens, where the shortly mown grass can also encourage it to develop. However, in recent years this has become more common in domestic lawns too, with the patches usually developing between mid-June and early October.

What causes it?

Dollar spot generally occurs during warm and wet conditions, so tends to happen in early Summer and autumn where warm days can be followed by wetter evenings. If your lawn is shady and lacks air movement, the lawn will sit damper for longer and may be more vulnerable to dollar spot.

If you take a ‘little and often’ approach to watering, this can also encourage the disease to develop, as the top surface of the grass stays wet whilst the soil below remains dry. Instead, you should only water 1-2 a week in dry conditions and heavily saturate the lawn. See our watering guide for further information.

Fungal spores can remain dormant in layers of thatch, and compacted soil restricts drainage so scarifying and aerating the lawn should be part of your maintenance regime.

Generally, mild outbreaks of dollar spot won’t cause any long-term damage as it only affects the leaf however severe and untreated outbreaks can kill the lawn or sports turf right back to the roots, this is especially evident in fine turf.

If your lawn is low in nutrient or has a PH imbalance, recovery may be restricted as the grass will be growing slowly and so will take longer for it to grow out and be cut off during mowing. When you do mow, ensure the blade is nice and sharp as bruised or damaged grass becomes more susceptible to disease. Adjusting the soil health and nutrient regime may reduce Dollar Spot attack in the future.