Poor watering and mowing habits, improper fertilizer application, and too much thatch often lead to turf diseases and problems in Bermuda grass lawns. You want to be able to identify these issues in order to fix them for good. But what are the common diseases in Bermuda grass lawns?
The most common Bermuda grass diseases include anthracnose, dollar spot, and rust. Infected grass will show color changes on the leaves and stems, powdery coatings, and greasy-looking grass. Armyworms and sod webworms also cause significant damage to Bermuda grass.
Some of these diseases and problems manifest in cold conditions while others are prevalent during hot and humid or dry conditions.
Is Bermuda grass prone to diseases?
Bermuda grass is susceptible to diseases especially when the turf isn’t receiving at least 4 hours of direct sunlight every day. Brown patch disease is one of the most common problems in Bermuda grass turfs established in areas that are often damp and receive inadequate sunlight.
This turfgrass requires enough sunlight every day to develop better resistance to diseases and pest attacks. Inadequate sunlight affects photosynthesis and denies the grass the energy it requires to grow into a thick, full turf.
Thatch is another major problem with bermudagrass turfs. Thatch build-up can keep air, fertilizer, and water from penetrating the root zone of the Bermuda grass and even harbor disease-causing insects.
Common Bermuda Grass Diseases
Bermuda grass is susceptible to diseases when you do not meet certain thresholds for optimal growth. The diseases include anthracnose, dollar spot, and brown patch disease. I will examine their characteristics and signs, causes, when they are prevalent, and the best treatment option.
Here are the common Bermuda grass diseases:
Anthracnose is a fungal disease that is common in Bermuda grass during warm weather. The symptoms of anthracnose that occur during warm, dry weather differ from those that occur during cool, wet weather.
Bermuda grass likes to grow in full sunlight. If your grass is under shade most of the time (where it does not receive at least 4 hours of sunlight) it will easily be attacked by anthracnose. This is often true if you water your bermuda grass lawn at night, leaving the grass blades wet overnight.
Signs of anthracnose
- Irregularly shaped yellow or brown spots on young Bermuda grass leaves
- Yellow spots with black centers in the leaves
- Rotting of basal stem and leaf sheath during cool-wet and warm-moist weather such as during spring and summer.
- Bermuda grass shoots infected with anthracnose are easily detached
- Small orange-brown blisters may appear on the grass stems.
Anthracnose can survive in your lawn for a long time in buds, fallen leaves or petioles, fruit, twigs, or buds. However, the fungal disease does not cause permanent damage to established Bermuda grass.
Best treatment option
- Reduce shade and improve air movement by pruning na thinning the surrounding vegetation.
- Brush or drag a hose across the surface of the Bermuda grass first thing in the morning to remove dew
- Aerate compacted areas on your turf
- Reduce excess thatch
- Water the grass early in the morning and not late in the afternoon or evening.
- Since Bermuda grass is susceptible to anthracnose, you can also consider planting disease-resistant grass.
This Bermuda grass disease is also caused by the fungi Claireedia homoeocarpa. Bermuda grass is most prone to dollar spots from late spring through fall. Warm daytime temperatures between 59°F and 86°F and fairly cool nights promote dollar spot growth.
The humid weather causes heavy dew formation on the Bermuda grass. Like anthracnose, dollar spot also forms colored spots. However, dollar spots appear on closely mowed Bermuda grass and are about two to six inches in diameter.
Bermuda grass is also susceptible to dollar grass if you water it often for short periods. However, there are ways to prevent and manage fungal disease.
Signs of dollar spot
- Circular and sunken straw-colored patches measuring several inches
- The patches on the Bermuda grass grow and merge, forming irregular shapes
- Reddish-brown margins along the leaf blades characterize light tan spots.
- The fungi attract moisture that can be seen early in the morning as a cobweb-like growth on the Bermuda grass surface.
- Bermuda grass blades appear water-soaked.
Best treatment option for dollar spot
- Prevent thatch buildup by removing excess thatch on your Bermuda grass
- Encourage quick recovery of Bermuda grass by applying adequate nitrogen fertilizer in spring and early summer.
- Set the mower at one or one-half inches high and ensure to mow the grass at regular intervals of five to seven days.
- Fungicides are particularly effective against persistent dollar spots. The best fungicide for dollar spot is Propiconazole and Fludioxinol.
- Ensure deep and infrequent watering to avoid drought stress. Avoid shallow watering and frequent irrigation schedules.
Bermuda grass rust is also a fungal disease that infects the grass when its growth is slowed. Rust is expected when the lawn receives excess moisture or dew. If, after heavy watering, the lawn takes more than six to eight hours to dry, rust will begin to form. Although it results in minor damage, prevailing factors can enhance rust severity.
You will come across the lawn grass rust fungus in late summer or early fall. During this period, the weather is dry, and the Bermuda grass is low in nitrogen. That encourages the spread of the fungi spores and thus rust in your lawn. Spore formation is promoted by fluctuating cool rainy nights with the bright hot daytime sun.
Signs and characteristics of rust
- Elongated yellowish leaf specks
- Red-orange fungal spores that, when touched, resembles rust from metal.
- Thin and weak lawn areas
- Large irregular rusty patches
Best treatment option for rust
If you do not care for your lawn, the rust can thin and destroy your good-looking Bermuda grass. In addition, they can remain there and infect new seeds.
Here are some ways to treat and prevent rust fungus.
- Use a balanced fertilizer that is rich in nitrogen.
- Frequent mowing at the recommended height
- Cut the Bermuda grass for hay
- Heavily graze over the grass to destroy the heavy canopy that promotes high humidity retention on the Bermuda grass.
Note that no evidence suggests that the rust toxins can harm livestock. Apart from diseases, other problems can encourage the degeneration of Bermuda grass on your property. Let’s take a brief look at them.
Other Problems with Bermudagrass Lawns
The other common problems of the Bermuda grass include the Bermuda grass mite, armyworms, sod webworms, and grubs. Like fungal infections, these problems are simple to identify and manage.
The Bermuda grass stunt mites occur in various colors. They can be translucent or creamy white but are elongated and so tiny they can barely be seen even under magnification. The mites can be seen under a magnification of 15 to 20 times.
The mites can damage and cause stunting of the grass terminals resulting in thin and bare spots on the lawn. Dethatching and one-inch watering after mowing will kill the Bermuda grass mites. The insecticides Diazinon or Baygon are also active against the mites.
You will see fall armyworms in Bermuda grass in May and early June. They have brown, green, red, or yellow stripes along their sides and back. Fall armyworms consume the grass foliage and can cause significant damage as they move in groups.
Therefore, if you can find three or four armyworm larvae per square foot of your grass, I recommend treatment. Instead of using granular pesticides, spray liquid pesticides such as Bacillus thuringiensis (B.t) products, carbaryl, or bifenthrin over the grass.
Additionally, proper lawn care, like watering every morning, will help your Bermuda grass recover from fall armyworms.
Sod webworms are buff-colored, half or three-quarter inches long Bermuda grass worms, also called lawn moths. Their most distinguishing characteristic is the snout-like extensions on their heads. They are particularly active through fall but disastrous in mid to late summer. You can notice them zigzagging over the Bermuda grass at dusk.
Treatment is recommended in the late afternoon or early evening before the sod webworms come out to feed. This problem can be treated by regular grass watering and fertilizing to enhance healthy grass growth and encourage recovery. Most importantly, you can also spray Bacillus thuringiensis over the grass when you notice larva.
However, desist from using broad-spectrum pesticides on Bermuda grass as they can kill essential predators on your soil. If you have any questions or need help with Bermuda grass disease and problems, reach us for expert opinions and recommendations.
The grass should be well fed to promote lush growth. Under typical situations, 1.5 pounds per 1000 square feet of slow-releasing nitrogen fertilizer is recommended. The fertilizer should have an N-P-K ratio of 16-0-8 to strengthen Bermuda grass and increase disease resistance.
Overfeeding or underfeeding with fertilizer may change the lawn soil pH and kill the grass. Consequently, overwatering can kill the Bermuda grass.
- A.M. Sutherland, University of California, IPM: Bermudagrass Mite
- Natalie P. Goldberg, NM State University Extension Plant Pathologist: Brown Patch Disease