Tuesday, April 5, 2011
Every spring homeowners get out the rake to clean up their yards and apply Jonathan Green fertilizers to wake up their lawns. There is nothing more pleasing than a spring green lawn to walk on and observe; much like the relaxing feeling you get while gazing at a fish tank. However, this year in late spring to early summer, it has been a particularly great year for fungus on lawns. The excessive rainfall has created the perfect breeding ground for fungus to attack your lawn.
Most fungus damage occurs from May through September. Many homeowners were surprised after their lawns looked so good. What went wrong? You need to be able to properly identify the “browning” of your lawn, whether it is coming from heat and drought stress, or from insect damage or fungus. In May of this year we did not experience any real long-term heat and drought stress. As I write this in June, the humidity is starting to appear more frequently, good for fungus… bad for your lawn. It is important that you do not treat your lawn for the wrong reason, like applying an insecticide when fungus or drought stress is the real problem.
Turf disease can be serious when weather and/or your lawn management practices favor disease development. Lawn diseases develop when several conditions occur simultaneously and persist. Fungi are microscopic, thread-like organisms and when the environment is favorable and a susceptible host is present, disease develops, much like in the human body. Wind, air, water, animals, people, insects and lawn mowers spread the spores of these parasitic forms of plant life! While lawn diseases are not always easy to diagnose, spots on leaves, leaf color, growth characteristics, time of year and temperature help to narrow the list down to a few disease possibilities, allowing proper treatments. A good food supply, proper temperatures and adequate moisture are important for continued disease infection.
Leaf spot is a common disease in home lawns appearing in spring and fall. Grass blades exhibit oval, purple leaf spots with some yellowing and thinning turf quality. Bluegrass, ryegrass and fescues can all be susceptible. To reduce or eliminate the chance of leaf spot disease, remove thatch, avoid heavy nitrogen fertilization, reduce excessive shade and do not mow too close.
Red thread is also a spring and fall disease than can infect bluegrass, ryegrass and fescues. Red thread is relatively easy to identify from its bright red thread-like strands of the fungus that form near the tips or cut surfaces of the leaf blade. Once red thread has arrived it is followed by a general yellowing and thinning of the turf. Avoid low nitrogen, remove excessive thatch and water properly so the grass does not suffer from drought stress, and apply a fungicide if necessary. Collect mowed clipping of red thread while you are trying to eliminate this disease.
Summer patch disease occurs during the hot portion of summer and can affect bluegrass and fescues. The initial symptoms are yellow patches 6 to12 inches in diameter. The turf thins out and rings of dead turf with green, healthy turf in the center remain and roots rot. Avoid high nitrogen, wet soil, compaction, and low mowing to reduce disease pressure. Aerify before symptoms develop and keep soil pH at 6.0 or above and apply Jonathan Green Lawn Fungus Control as needed on a preventative or curative basis.
Dollar spot can infect bluegrass, ryegrass and fescues. It produces 2 to 3 inches straw colored patches with bleached centers and orange borders, thus the name dollar spot, like a silver dollar. Early in the morning, when the grass is covered with dew, a faint cobwebby growth may be seen on the leaves of infected plants. Dollar spot is a summer disease that favors heat and humidity to form. Maintain adequate nitrogen fertility, water in the early morning hours, and reduce thatch if it is present. Treat dollar spot with Jonathan Green Lawn Fungus Control.
It is helpful to review the past few months of treatments on the lawn including mowing height, fertilizer applications, watering practices and rainfall to target your next action for control, whether it is changing your maintenance practices or applying a Jonathan Green fungicide. Sound cultural practices are usually adequate to prevent serious lawn disease damage and influence turf vigor. These include, selecting the proper Jonathan Green grass seed mixtures adapted to the area, proper watering techniques, and timely Jonathan Green fertilizer applications, regular mowing at recommended heights, adequate sunlight and air movement, good soil drainage through aeration and thatch management. Wow, that’s a lot to keep track of!
Your lawn can only be as good as the quality of grass seed you sow. Using Jonathan Green high quality varieties are the key to a healthy lawn in the long run. The best defense from fungus, bugs and weeds is a healthy, thick, growing lawn that can withstand heat and drought stress better than poor performing common-type grass seeds. Picking the proper species that adapt to the area of the lawn like kentucky bluegrass for sun areas and not shade areas will help to avoid lawn disease problems. Tall and fine fescues and perennial ryegrasses help to provide species diversity to your lawn. If a certain disease comes along that wipes out kentucky bluegrass, the other grass species will hopefully live so you can avoid losing your whole lawn.
Water, water, everywhere! How many times have you been driving to work in the rain and see someone’s sprinkler going full blast? Water is expensive and replacing your lawn because of fungus is expensive too. Too much or too little of most things are not good; this includes water on your lawn. The average lawn during the growing season needs about one inch of water whether from rainfall or sprinklers. Fungi easily penetrate turf grasses with wet, succulent tissues. Water logged soils inhibit gas exchange and results in dysfunctional roots and a weak grass plant. It is critical that you do not water from dusk until dawn. It is better to water your lawn in the daylight hours rather than at night so the lawn has a chance to dry out and not have constant moisture surrounding the grass blades. Deep, infrequent watering to avoid drought stress is best, and will results in less chance of a fungus developing.
Follow the Jonathan Green Annual Lawn Care Program when feeding your lawn. Use Jonathan Green fertilizers that contain some slow release nitrogen so you do not promote too much top growth. Many lawn diseases also appear due to the lack of fertilizer. Remember, the rule of life, too much or too little of anything, including fertilizer, is not good for the lawn. Look for the “Guaranteed Analysis” listed on the back of any Jonathan Green fertilizer bag to see if that fertilizer has any ‘slow-release’ characteristics. These will include under the Nitrogen (N) listing either Water Insoluble Nitrogen (WIN), or a Slowly Available Nitrogen statement.
Consider switching to a Jonathan Green Organic Lawn Care Program, which feeds the soil, which then feeds the plant. Allowing the soil to slowly supply plant food to the grass plants, as they need it over time, should reduce disease development in your lawn.
Mushrooms are a living fungus, sometimes called fairy rings and can be poisonous. Fairy rings are difficult to control and it may not be practical to remove them. To eliminate mushrooms, mark out an area at least one foot beyond the ring and remove all soil to a depth of one foot. Remove any thatch and organic matter such as decaying wood from old trees left in the ground to eliminate the mushrooms food source. Be careful not to spill any of the soil as you remove it on the lawn. Refill the hole with new soil and reseed. Reseeding is preferred over sod reducing the danger of reintroducing the fairy ring fungi. If you wish to avoid this process, go to plan B. Plan B consists of fertilizing properly to help mask the symptoms and punching holes every foot or so down to one to two feet. Use a hose to pump large amounts of water into the ground. Increasing the soil moisture changes the ecological balance hopefully enough to retard the growth of fairy rings. Aeration also reduces the symptoms severely. Mushrooms that do appear can be raked up and destroyed, minimizing danger to children and pets.
If fungus persists over the years in shady areas, trim some lower growing tree branches to let sunlight filter onto the grass for better growth. This also helps to prevent moisture from lingering on the grass blades. Airflow is improved to help dry out wet grass. Fix drainage problems and aerate your lawn if you have not done so in the last five years. Thatch build up can be a problem and promote fungus. Rake the lawn vigorously to remove thatch or rent a power-thatching machine to aid in this process.
There are times when the application of a Jonathan Green fungicide, like Lawn Fungus Control, is necessary to prevent further spread of a fungus or your whole lawn being wiped out. There is a preventative rate and a curative rate to apply the product. Our fungicides are labeled for use on a number of diseases and come in both granular and liquid forms. A repeat application in 21 to 30 days is sometimes required. Please be careful to read the label and follow all directions for best results, follow the guidelines listed above and hopefully your lawn will be fungus free in the future.Back