St. Augustine Grass Diseases and Problems
The various St. Augustine grass diseases are ‒ Nigrospora Stolon Rot, Gray Leaf Spot, Brown Patch, Fairy Ring, Chinch Bugs, Take-all Root Rot (TARR), and different problems associated with it are cold damage and white grub worms.
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St. Augustine grass remains vulnerable to many fungal diseases, including infestations and weeds. These issues can negatively impact your grass, leading to bad color patches in your lawn and thus making it ugly. However, the good news is that you can quickly fix these issues with practical solutions.
1. Nigrospora Stolon Rot
This new disease appears mainly on the runner or stem of the grass and keeps the stolon suffering by keeping the nutrients and water away. This adds extreme moisture stress, thus making it completely desiccated. The issue remains at its peak during the dry season of springs and summers. The rise of temperature brings in stolon rot in the grass.
It also brings in issues, including fungus, thus enlarging the stolon and griddle. This issue further reduces the water movement and nutrients reaching the leaves. Eventually, the leaves of the grass will die down, making it yellow. Adding the new growth to the grass will only make it yellow and thin.
The best way to prevent this disease is to water the grass adequately, especially during summer. To treat it, apply a quality commercial fungicide.
Allowing this problem can make the leaves wilt and become yellow, causing the death of the infected leaves. The only preventive measure against this ailment is to keep the grass watered with adequate quantity.
2. Gray Leaf Spot Disease
The root cause of Gray Leaf Spot disease is Pyricularia Grisea which causes perennial ryegrass and tall fescue to move smoothly in rainy and warm climates. The spot on the grass leaves comes in the form of an oval and round in color, having dark brown borders.
High humidity or when the leaves are completely wet, the leaf spots make them fuzzy and gray, perfusing spore production. The leaf spots extend with time, allowing the leaf to wrap. These issues cause the leaf’s death coming from the tip. The harm to your lawn starts when this disease progresses faster.
The disease’s early symptoms include having gray spots on the leaves of small spherical size and having a yellow mark around them. The disease is difficult to discover as the gray leaf appears like rust. However, with time they grow in size, becoming gray spots.
If you notice a high pressure of this disease, frequent fungicide application can help reduce the impact on yield. However, these applications remain expensive and prove effective only when you find the disease pressure to be high.
3. Brown Patch Disease
Brown patch is a disease or fungus that hampers lawn conditions with one species of fungus known as Rhizoctonia. These often occur during the mid or late summer season during the humid and hot weather. These allow the best conditions for fungus to thrive. It has no impact on the roots or crown of your turf plant.
The diagnosis of this disease helps pull away from the affected blades, as seen on the attached runners. If you notice the pull quickly, it confirms the advent of this disease. The other symptoms include wet grass for an extended duration after being closely mowed.
To treat this disease in the grass effectively, you can rely on commercial fungicide use with the help of several active ingredients. These include Myclobutanil, Thiophanate Methyl and Azoxystrobin.
However, to prevent the disease, make sure to have good drainage, soil aeration, dethatching, and regularly watering. Lastly, it would help to avoid fertilization when the weather is cool.
4. Fairy Ring Disease
Fairy ring disease is among the chronic and common issues of turfgrass found in several places like home lawns, sports fields and golf courses. These are mostly seen during the spring, summer and fall seasons.
The presence of disease is often confirmed by three symptoms: stimulated growth, mushrooms, and necrotic rings/arcs. The fundamental cause behind the grass is a specific soil fungus known as basidiomycetes.
These fungi sustain in sandy soils, which carry less soil nitrogen and minimal moisture. Also, the addition of thatching can offer some favorable conditions for the fungi. These are often the result of forming a fungal mat, which further avoids water absorption into the surface.
The good news is that you can quickly treat this disease whenever you find it on St. Augustine grass on your lawn or yard. The best option is to eliminate the turfgrass found in the areas and lay the sod depending on the required quantity.
5. Chinch Bugs
These small insects can be seen using a magnifying glass on your lawn only when damaging the grasses. These remain active in high-temperature conditions; hence you can find them during summer. When young, they are found in red; however, as the insects mature, they transform their color to black with a white spot on their back having the X shape.
They only move in groups from an infected area to a fresh lawn at an average speed of 40 feet per hour. These are mostly found inside the thatch layer of your yard. However, they are seen everywhere, crawling over the grass when they are in large numbers.
They damage the grass significantly by sucking all the juice from the grass blades and injecting the leaf blade, which can further cause the grass to die.
You can notice their presence on your lawn once you find irregular patches. These resemble drought stress. You can find them becoming yellow, followed by brown, and the grass dies at the end. Soon you will find weeds overtaking the yellow dead grass on the lawn.
These insects become resistant to certain insecticides. Even though the insects die, their eggs remain untouched, bringing their next generation.
The only way to prevent these insects is to maintain your lawn regularly. Proper maintenance includes watering adequate quantities of the grass and applying nutrition. You can get away with these insects by using a suitable pesticide or insecticide on the affected grass in your lawns.
6. Cold Damage
During winter, the lawns with St. Augustine grass can become brown. However, this remains a usual story during the winter days, and as spring arrives, the lawn rebounds and adds new green growth. However, if the winters hit hard, you notice the grass getting injured.
Your lawn will face permanent damage once the temperature drops below 20 degrees F. Initially, the grass may appear wilted and become brown or whitish. The higher vehicle and foot traffic will only worsen the grass on your lawn. If you find the lawn in bad shape, you need the patience to see the winter months pass away.
It will give your lawn the time to recover before starting the mowing process. Once you mow, make sure you cut the lawn grass at the highest height. Cutting the grass to a small height will prevent it from recovering from the cold damage.
7. Take-all Root Rot (TARR)
The Take-all Root Rot is classified as a fungal disease. It brings in dead, brown and weak patches on lawn grass. The disease in regions like Florida is also called bermudagrass decline. It is caused by St. Augustine grass, mainly in the coastal areas of the United States, which receive high rainfall and have sandy soils.
The cause behind this disease is a fungus known as Gaeumannomyces graminis var. Graminis are mostly found in the soil. You can find this fungus in different parts of Texas. These are found in thatch and the decaying plant matter.
The fungus produces spores, but at the same time, it spreads over the stolons and roots. The symptoms of this fungus are evident during the spring or the early summer after winter dormancy.
Soon you will find the grass is stressed by drought, heat, high sodium water or alkaline soil. Some initial symptoms are seen in the form of yellowish foliage, which makes it wilt and brown. As the grass becomes thin, you can see the brown patches on your lawn in irregular patterns.
Preventing this fungus is the only best approach to this problem. You need healthy root development, allow good drainage below the soil surface and avoid overwatering. You can be irregular in watering rather than giving the grass frequent water. Lastly, test the soil and then fertilize regularly as per the test outcome.
8. White Grub Worms
The white grub worms are primarily found in humid temperate locations like Florida. These are six-legged insects mostly found close to their heads. They have a C-shaped body appearing shiny and slick. They follow a similar life cycle and give similar damage while they eat the grassroots.
They prevent the grass-root from extracting nutrients and water, eventually allowing the grass’s death. They often damage the grass but only in severe cases do we see them killing the entire lawn. It is not easy to diagnose the grub issues as they dwell underground. However, as you check the yard becoming thin and yellow, you can make out their presence.
The best way to find out the presence of white grub worms is to use a shovel to dig the soil and find out the worm underneath.
The best way to avoid these worms is to adopt cultural practices for keeping a well-maintained and healthy lawn. However, you can rely on chemical treatment if you find severe damage. These can quickly kill worms and make your lawn healthy.
In conclusion, the various St. Augustine grass diseases are ‒ Nigrospora Stolon Rot, Gray Leaf Spot, Brown Patch, Fairy Ring, Chinch Bugs, Take-all Root Rot (TARR), and different problems associated with it are cold damage and white grub worms. Contact Eden today for professional routine lawn care services and keep your lawn healthy and lush green.
Grass cutting taking up all your time? Call us, and we will do it for you!