Dollar Spot is another of the common lawn diseases which can affect Saint Augustine grass and is most commonly seen in Spring through to Fall. Dollar spot is most noticeable by its patterns of small spots of discolored grass, which are most often 1 to 4 inches in diameter and can spread across the surface of the lawn, or may be restricted to only some areas of the turf, or the spots can even join together to create larger irregular patterns. However, we will still identify dollar spot most easily because of those same straw colored spots on our St Augustine lawn that are about the size of a large coin.
An inspection of discolored leaf of turf affected by Dollar Spot will reveal small legions on the leaf which are most often shaped like an hourglass, and on cooler mornings the affected areas of the lawn will appear to have fine white spider webs across it which is most noticeable with the morning dew. However, once the dew has subsided and the day has warmed up, these "spider webs" will disappear. The webs themselves are actually a byproduct of the fungal disease, called Mycelium threads.
Causes Of Dollar Spot In Saint Augustine Grass
Lack of soil nutrients and excess moisture in the turf sward are the most common promoters of dollar spot disease in Saint Augustine grass.
This means that lack of fertilizer and bad watering habits are the primary culprits causing and promoting Dollar Spot in Saint Augustine grass, as are also the most common reasons for almost all lawn diseases. Additionally, any other factors which are weakening the lawn can also contribute to any outbreak of lawn disease.
Treating Dollar Spot In Saint Augustine Grass
Dollar Spot can be treated by use of fungicides, but it really is not necessary, and without treating the actual cause of the outbreak of the lawn disease, we're really just asking for more of the same from new infestations of dollar spot or any number of other lawn fungal diseases in the future.
The key to curing and preventing dollar spot in St Augustine grass is good lawn care.
Begin implementing a good year round fertilization regimen, using a good quality lawn fertilizer. Nitrogen deficiency is the major cause here, so be sure to use a fertilizer higher in Nitrogen for the period of treating dollar spot.
Keep the lawn mowed regularly throughout the year so as to keep excess thatch and excess lawn leaf under control, because this is where the disease will flourish.
Water only in the mornings, and try to reduce excess watering wherever possible. Aim to water less often, but by applying more water at each watering. This will train the roots of the turf to go deeper into the soil, making the lawn more drought tolerant, as well as removing the frequency of water left sitting in the thatch layer of the lawn for too long.
Regular de-thatching and lawn coring of the soil and turf will also aid in reducing the prevalence of dollar spot in Saint Augustine grass.
The key here is to make the lawn as healthy as possible by creating an environment which is most favourable to lawn health, while at the same time creating conditions which are hostile to the lawn disease.
In this way, the Saint Augustine lawn should in most cases destroy the dollar spot on its own.
If in the end, after we've improved the lawn care practices to our lawn, and dollar spot is still prevalent, then we should look at using a lawn fungicide to aid in the treatment of dollar spot in our Saint Augustine lawn.