In the final part of our series on lawn disease we look at the disease known as Leaf Spot. Leaf Spot – or “melting out” in severe cases – is a common turfgrass disease in the United States, affecting a wide range of different grass plants. In northern climates such as ours, Leaf Spot damage occurs first in the spring and again in late summer to early fall. Let’s explore more about this common lawn disease.
Common Aspects of Leaf Spot
- Leaf Spot can be identified by purplish-brown to black colored spots with tan centers on the leaf blades and sheaths of your turfgrass. As these dark spots or lesions expand, the center becomes lighter in color with a dark brown to black border. The “lesions” may also be surrounded by a yellow halo and the lower leaves can eventually become shriveled and wilted.
- Conditions needed for Leaf Spot to occur include: the pathogen Bipolaris spp., or Drechslera spp., a host includieng Bluegrasses, bermudagrass, fescues or perennial ryegrass, and environmental factors such as: moist to wet climates with temperatures ranging from 40-80 degrees Fahrenheit and soils with high nitrogen levels.
- Tips for controlling Leaf Spot include: increasing the mowing height of your lawn, avoiding excessive application of fertilizers with water-soluble nitrogen in the spring,
minimizing the amount of shade and increase air flow, and
irrigate as infrequently as possible (when irrigation is performed, irrigate turf deeply).
- Management techniques can also include: removal of the area of grass that is infected, keeping foliage dry, and use fungicides only when needed. If you are questioning the proper treatment of your lawn disease call Pro-Tech Lawn Care to schedule and appointment today. We can inspect the are and determine a proper course of treatment to manage your lawn disease issue.
In today’s part four of our series on lawn disease we examine the damage of the lawn disease known as Fairy Ring. Centuries ago people thought that mushrooms appeared where “fairies” had danced the night before-hence, the name, “Fairy Ring”. Fairy Rings may sound magical and mysterious and somewhat romantic but the reality is that these circular rings of mushrooms are, in fact, disease.
Fairy Rings commonly appear in any lawn, golf course or other turf areas during spring and summer months. The rings appear as either dark green or brown circular bands ranging in size from a few inches to 50 feet in diameter. The fairy ring fungus grows outward from a central point at a rate varying from a few inches to as much as several feet a year.
Common Aspects of Fairy Ring Disease
- There are three kinds of fairy rings. One type has no mushrooms. Another has mushrooms and stimulated grass growth and still, the third type contains only a ring of mushrooms, with no evidence of unusual grass growth.
- Fairy ring fungi do not attack grass directly, but break down organic matter in the soil. As a result, nitrogen is released, which the grass uses, causing it to grow and develop a contrasting green ring.
- The mushrooms of a Fairy Ring can be poisonous to young children so, immediate elimination is needed to protect both children and pets.
- Dark green circles, arcs, or rings of thick, fast-growing grass develop anytime from green-up in the spring (most common) until the first hard frost in the fall.
- Management strategies include: proper fertilizing, aeration, and seeding. Other strategies also include removal or destruction of the disease. Removing the ring area may include digging up the area and feeding the grass appropriately. In addition, eliminate thatch buildup with a de-thatching program. Finally a fungicides may be needed to suppress a Fairy Ring outbreak.
- Call Pro-Tech Lawn Care to schedule and appointment. Experience technicians can inspect your lawn and make appropriate recommendations.
As we continue our series on Lawn Disease, we take a look at a common and destructive disease called Plythium Blight. This particular disease is also known as grease spot, cottony blight, or Pythium Root Rot. It can affect a variety of turfgrass species throughout the United States and is most common in our region during the humid summer months.
Identifying Plythium Blight
Pythium Blight causes greasy, brown, circular spots that are 3/4 of an inch to 2 inches in size, and grow rapidly. These spots are water soaked and dark colored early in the morning. Diseased patches then fade to a light brown or gray color. With high humidity in early morning or throughout the day, diseased leaves may be covered with the white, cobwebby, mold-like growth of the causal fungus. Severe outbreaks can completely destroy the turfgrass within a few days if weather conditions favor disease development.
Aspects of Plythium Blight
- Plythium Blight can lead to an infection in your lawn if all of the following conditions are present: the pathogen Pythium aphanidermatum, a host grass such as Host – Annual bluegrass, bentgrass, bermudagrass, perennial ryegrass and tall fescue, and environmental factors such as: Environment – hot, humid climates with temperatures in excess of 90 degrees Fahrenheit in the daytime, 68 degrees nighttime.
- Plythium Blight controls can include cultural control tips such as: avoiding mowing wet, infected turf where mycelium is present to avoid spreading spores with the mower blades.
Reduce thatch and improve drainage with core aeration. Water infrequently but deeply, and avoid watering at night. Homeowners can control these aspects of lessening the damage and spread of the disease.
- Call in lawn experts for best results such as Pro-Tech Lawn Care who can examine the lawn and decide on a proper course of treatment.
As we continue our series this month on lawn diseases we would like to examine one disease that is fairly common to this region – Red Thread. If you have noticed circular patches that are tan, red or pink in color and about 4-8 inches in diameter then you may have Red Thread (also known as Pink Patch). Red Thread symptoms create an undesirable appearance, but crowns and roots are not infected. Red Thread will catch your attention as you mow or care for your lawn.
Common Aspects of Red Thread-
- Red thread most commonly affects Kentucky blue- grass, perennial ryegrass, and tall fescue. Outbreaks usually occur in low maintenance turf stands such as residential lawns, golf course roughs, and some low budget athletic fields. Red Thread also is common in damp, slow-growing, nitrogen-deficient turfgrass.
- Red Thread is often associated with malnourished, low-quality, slow-growing turf.
- One of the biggest contributing factors in the appearance and spread of red thread lawn disease is low soil fertility.
- Poor watering habits and drainage can also be a contributing factor to this lawn fungus.
- Overseeding or replacing susceptible grasses with resistant varieties is helpful in controlling this disease.
Disease development occurs over a relatively wide range of cool conditions (40-70° F), typically in the spring and fall, especially during long evening dew periods.
Control Methods for Red Thread
Professional technicians can inspect your lawn and help you with specific watering habits and balanced fertilization programs. The most important non-chemical (cultural) control option involves implementing an adequate nitrogen fertility program. Chemical control is also an option but not always needed. Fungicides may be used to control Red Thread if outbreaks occur on high maintenance turf or high value properties.
Do you have weird brown patches in your lawn? Do the grass blades look shriveled or shredded? You may have lawn fungus and not even be aware that it is running rampant in your yard. Don’t be embarrassed. It can happen to any lawn. No one is immune to the diseases that find their way into our landscaping.
The most common signs that you have a lawn fungus include the following symptoms:
- Bleached turf
- Stunted growth
- Shredded or shriveled grass blades
- Lesions on leaf
- Dark growth at the base of the plant
Most Common Forms of Fungus
There are many varieties of lawn fungus that can attack your lawn depending upon the types of grass, the climate and the local conditions. These include:
- Leaf Spot/Melting Out – Tiny, circular, dark spots or larger purplish spots, favored by cool air temperatures, moist conditions and improper mowing.
- Red Thread/Pink Patch – Small, light pink to red patches, favored by cooler weather and moist conditions.
- Dollar Spot – Circular patches with reddish-brown borders, favored by humidity.
- Brown Patch – Circular, light brown patches, favored by moist conditions or areas that remain wet.
- Fairy Ring – Circular patches of dark green, often enlarged into rings, favored by mild temperatures and moisture, and sometimes in dry, hot conditions.
- Rust – Small, yellow flecks on leaves, sometimes enlarged to form rust-colored pustules, favored by moderately warm and humid conditions or stressed turf.
What Causes these Fungi?
While the cause of the fungus in your yard may be linked to the conditions, type of grass and region, in general lawn fungus are caused mainly by: cool or warm temperatures, over-or under-fertilization, unbalanced fertilization and certain watering habits. All of these situations can contribute to the onset of a lawn fungus or lawn disease. Since lawn fungus and diseases can wreak havoc on your beautiful lawn we suggest an inspection by our professional technicians. Call Pro-Tech today if you recognize any of the symptoms of lawn fungus.
Check back for our blog series on lawn disease this month as we examine more closely the types of disease common to our region.