Lawn Fungicide | Using the Correct Treatment to Combat Lawn Disease

Keith Hardy - Bio Photo
Keith Hardy
Senior Editor

Keith has been involved in the gardening and landscaping industry for the past 21 years. From a jobbing gardener to running his own landscaping services....

Lawn fungicides are used to keep your lawn healthy and free of unwanted pathogens. Most people want their lawns to look lush and green but often lawns can in places appear scarred or discolored.

There are actually quite a few reasons why your lawn might look sickly and fungal diseases are usually to blame. However, once you know and understand the cause curing it can be simply a matter of applying the correct curative steps which can involve lawn fungicidal treatments.

What Are Lawn Fungicides?

Lawn fungicides are treatments that are applied to a lawn or to eradicate or prevent the growth of grass diseases. These diseases are the result of grass fungi and other microorganisms infecting a lawn or grass area.

Lawn fungicide treatments are applied to eliminate these fungi such as lawn rust and prevent the diseases from affecting the lawn. Lawn fungicide treatments can be part of a comprehensive lawn program or can be used independently to treat a lawn that has been affected by a specific disease.

How Lawn Fungicides Work?

Fungicides are usually made up of two parts: one that kills the fungus and another that prevents it from growing back. The most common fungicides used in lawn care include copper sulfate, mancozeb, and azoxystrobin.

It is important to note that lawn fungicide does not heal or repair sick grass, but rather offers a curative reaction by inhibiting the development and spread of fungus in the plant.

In order to be effective, liquid fungicides must penetrate into the soil and reach the roots of grasses. Granular fungicides work by clumping together and settling out onto the surface of the ground. These types of fungicides are less likely to penetrate deep enough to treat the root zone of the plant.

It is particularly important to use liquids since they have a wide range of control and may be used to offer preventative, systemic, and curative activities. Because resistance might build over time, it is critical to alternate between various ways of acting. So if using Propiconazole and azoxystrobin applications their use should be rotated.

Using Lawn Fungicides To Cure Lawn Diseases

Lawn fungal diseases - red thread

Lawn fungal diseases only occur when the following three elements are present –  a host (the grass) a pathogen (the grass fungi) and the correct environment (temperature, humidity, and moisture). Thus a pathogen can only attack and tack hold if there is a vulnerable host during a time period in which the necessary environmental circumstances are favorable for infection and disease development.

If you want to cure a lawn disease, you may not need to resort to using chemicals. There are many natural ways to kill weeds and pests without harming plants.  Options include using diatomaceous earth, which is a naturally occurring substance found in soil. It works by absorbing moisture and killing insects.

If you choose to use chemical fungicides there are a plethora of choices on the market. These can broadly be split into two different camps broad-spectrum fungicides and narrow-spectrum fungicides.

Categories of Lawn Fungicides

Fungicides are categorized based on how they act against the fungus and also how they act on the grass blade. Fungicides that have the same ‘mode of action’ in fighting the fungi function in a comparable manner to them and are classed together.

To protect plants against pathogen infection, contact-type fungicides are applied directly to the leaves of the plants. When used before symptoms become obvious, they may prevent infections from forming; but, pathogens that have already developed will continue to progress unless they are treated. Systemic fungicides enter the plant, however, their mobility within the plant is restricted by the plant’s structure.

When applied to the leaves, the great majority of fungicides travel upward in the plant’s vasculature but do not reach the roots. Some fungicides only penetrate into the treated plant portion on a localized basis. Some systemic products have a curative effect, which implies that the illness is halted in its tracks before it can progress.

Broad-Spectrum Fungicides

As the name suggests these broad-spectrum fungicides can be used to treat a wide variety of different grass fungi that may have infected your lawn

These broad-spectrum fungicides are usually very effective at eliminating grass fungi problems. Broad-spectrum fungicides have the ability to control a large variety of diseases that are not connected to one another. You will find that the vast majority of contact fungicides are classified as broad-spectrum.

A broad-spectrum fungicide should be used early in the growing season to help minimize numerous fungal troubles later in the summer or fall.

Narrow-Spectrum Fungicides

Narrow-spectrum fungicides are lawn fungus management solutions with a narrow range of activities and are beneficial for treating certain species of fungi.

They are only effective against a small number of diseases that are frequently closely related. These are often limited to a particular location and are frequently systemic in nature. 

They tend to be used when you have a prevalent or stubborn problem with particular fungi. 

How do you mix lawn fungicides?

Lawn fungicide products come in two forms: liquid and granular. The liquid form is usually applied by spraying it onto the leaves of the grass, whereas the granules are spread out on the ground. Both types of products contain different active ingredients, so it’s important to read the label carefully before applying any type of pesticide. Once you know what kind of product you’re using, follow the instructions on the package.

How long does it take for lawn fungus control to be effective?

It takes between 7 to 10 days for lawn fungus control to take effect. If you don’t see results after this period, contact your local lawn care service provider. They may not have used the right mix of chemicals or they might have missed some spots.

When is the right time to apply lawn fungicide?

The best time to apply fungicides is during warm weather months from April through September. This will ensure that the chemical has enough time to penetrate into the soil before cold temperatures set in. In winter, it’s better to wait until spring.

How to Know if Your Lawn Needs a Fungicide Treatment

If you notice leaves turning yellow or brown, this could mean your lawn needs some kind of treatment. It’s important to note that not all plants respond the same way to fungicides. Some types of grasses may show signs of damage while others will remain unaffected.

How frequently can fungicides be applied?

Lawn fungicides are packaged with detailed instructions. Using too much or too little may be just as detrimental as using too much or too little. Some individuals want to forgo using pesticides altogether and instead use natural fungicides instead. Even if you are using a natural on non-biological fungicide, you must adhere to the manufacturer’s instructions to the letter to avoid possible lawn damage.

As a general rule though you apply fungicide about once every two weeks during the growing season. You can also use the following tips to determine whether or not you need to apply fungicide:

• Look for dead patches of grass.

• Check for white powdery patches on the grass leaf blades.

• Examine the underside of the leaf for signs of fungal infection.

• Check for dark-colored areas on the undersides of the grass blade.

• Observe how well the grass grows in comparison with other parts of your lawn.

• Check for new growth coming up through the turf.

• Watch for yellowing or browning of the leaves.

Keith Hardy - Bio Photo
Keith HardySenior Editor

Keith has been involved in the gardening and landscaping industry for the past 21 years. From a jobbing gardener to running his own landscaping services. He is now dedicated to bringing you the latest in gardening news. Read more

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