Lawn Fungicide: Effective Mushroom Killer?

Mushrooms in lawns can be unsightly and even dangerous if you have children or pets. While fungicides are often used to treat and kill lawn fungi, they don't directly kill mushrooms. Instead, they can prevent, kill, or inhibit fungal growth. The best fungicide to use depends on the specific fungal disease affecting the grass. For example, Headway G (azoxystrobin and propiconazole) is a broad-spectrum granular fungicide that targets common lawn fungi like brown patch and dollar spot. Pillar SC (triticonazole and pyraclostrobin) is a fast-acting liquid fungicide that controls common turfgrass diseases. To effectively manage mushrooms, aeration is necessary to break up the dense fungal mat of mycelia.

Fungicides don't kill mushrooms directly

Mushrooms are a type of fungus that grows underground and releases spores to reproduce, which can lead to more mushrooms. While fungicides can be used to treat and kill certain types of fungi, they don't directly kill mushrooms. This is because the main portion of the fungus lies underground, out of reach of fungicides.

Fungicides are classified as pesticides and can prevent, kill, or inhibit fungal growth. They are commonly used to treat fungal diseases that affect grass, such as brown patch, dollar spot, and fairy ring. However, they are not effective against bacteria or viral diseases.

Commercial fungicides, such as azoxystrobin or flutolanil, can be used for large outbreaks of mushrooms. These must be applied multiple times by a professional. It's important to note that a healthy lawn has a lower chance of growing mushrooms, so proper lawn maintenance, mowing, and watering can deter fungal growth.

To effectively manage mushrooms, aeration is necessary to break up the dense fungal mat of mycelia. Additionally, removing the mushrooms by digging them up with a trowel or shovel and disposing of them properly can help prevent the spread of spores. Applying fertilizer to the affected spots can also promote new grass growth and speed up decomposition to prevent mushroom growth.

While fungicides don't directly kill mushrooms, they can be used as a preventative measure in areas where fungus has been a problem. Jonathan Green's Lawn Fungus Control, for example, can be applied to cool or warm-season lawns to prevent and control turf diseases. However, it's important to read and follow all instructions when using any fungicide product.

Mushrooms are a sign of good soil

Mushrooms are harmless to plants and can even act as a natural pesticide when ingested by insects. They are also a sign of fungal active soil, which is beneficial for trees, shrubs, and other organisms that thrive in such an environment.

However, it is important to note that while the majority of mushrooms are harmless, some species are toxic. Therefore, it is not advisable to eat mushrooms found in your yard or lawn. If mushrooms are growing at the base of a tree or on its bark, it could indicate decay in the wood, and professional advice should be sought.

To discourage mushroom growth, proper lawn maintenance, such as regular mowing and adequate watering, can help create an environment less conducive to fungal growth. Additionally, fungicides can be used to prevent, control, or inhibit fungi growth. Commercial fungicides, such as azoxystrobin or flutolanil, can be applied by professionals to address large outbreaks. However, it is important to identify the specific fungal disease affecting the grass before selecting an appropriate fungicide.

Lawn fungus can be prevented

Lawns are naturally full of fungal spores, which usually don't cause any harm to your grass. However, certain conditions can cause these spores to germinate and lead to diseases like red thread, brown patch, dollar spot, and leaf spot.

To prevent lawn fungus, it is important to maintain a healthy lawn by mowing and watering it properly. Proper watering will deter fungal growth. Overwatering can cause mould, mildew, and yard fungus to form. Once your grass is established, water deeply but less frequently. Your grass only needs about an inch of water per week. Water early in the day so the grass will dry in the sun; wet grass is more susceptible to fungus.

Leaving piles of leaves, branches, and other debris creates the ideal breeding ground for fungus. Improve drainage by fixing low-lying areas or spots that don't drain well to prevent water from pooling. Test the soil to check for nutrient deficiencies, which can weaken grass plants and make them more susceptible to disease.

Fertilisers can also be used to promote new grass growth and speed up the decomposition that will prevent mushroom growth. Jonathan Green's Lawn Fungus Control is a broad-spectrum granular grass fungicide that can be used as a preventative measure in areas where fungus has been a problem in the past. It can be applied to cool or warm-season lawns in spring, summer, or fall.

Types of lawn fungus

While lawn fungicides can prevent, kill or inhibit fungi growth, they are ineffective against bacterial or viral diseases. Contact fungicides, also known as protectants, are not absorbed by the plant but stick to leaf surfaces, creating a barrier that prevents the fungus from entering and infecting plant tissues. Penetrant fungicides, on the other hand, are absorbed by the entire plant, while preventative fungicides require direct contact with the fungus and may need reapplication.

Brown Patch

Caused by the fungus Rhizoctonia solani, brown patch is one of the most widespread lawn diseases. It appears as circles of dead, sunken grass that vary in size, from a few inches to several feet. The grass blades darken, wilt and die, leaving a smoke-grey perimeter. Perennial ryegrass, tall fescue, bentgrass and Bermudagrass are most susceptible to brown patch, although Kentucky bluegrass, fine fescue grasses and St. Augustine grass are also commonly affected. Brown patch thrives in hot and humid weather, with wet leaves, high humidity, overfertilising and excess water facilitating its spread.

Dollar Spot

Dollar spot is a fungal disease that affects residential lawns with cool-season grasses, such as Kentucky bluegrass, perennial ryegrass and fine fescue. It gets its name from the small, round straw or tan-coloured spots, about the size of a silver dollar, that appear on the lawn. These spots may have reddish-brown borders and can merge to form larger patches of dead or dying grass. Dollar spot is caused by the fungus Sclerotinia homoeocarpa, which flourishes in warm and humid conditions, spreading through grass blades, lawn equipment, shoes and other tools.

Fairy Ring

Fairy ring is a lawn fungus that appears as dark green, circular bands in the early summer. It can also manifest as unformed circles. Fairy ring is caused by a fungus that feeds on organic matter in the soil, such as tree stumps or dead animals, and it may prevent your lawn from absorbing nutrients.

Powdery Mildew

Powdery mildew is a fungal disease that can infect any turfgrass but is most prevalent on Annual Bluegrass, Bentgrass and Fescues. It causes a white or greyish powdery coating on the leaves and stems, feeding on plant tissue and causing damage. The affected leaves may turn yellow or brown, and the grass may become stunted and weakened. Powdery mildew occurs in cool, humid conditions, typically in spring and autumn, and it spreads rapidly in shaded areas with poor air circulation.

Pythium Blight

Pythium Blight is a fungal disease that affects all types of turfgrass, including lawns, golf courses and sports fields. It causes the grass to turn brown and die, sometimes within a few hours. Pythium Blight is identified by dark, greasy-looking spots on the lawn, which may also have white fluff.

How to kill mushrooms

Mushrooms are a type of fungus that grows underground and releases spores to reproduce, similar to how seeds spread. While mushrooms are beneficial to the ecosystem of your yard, breaking down organic material into nutrients for your lawn, they can be a nuisance and even dangerous if you have children or pets. Here are some ways to kill and prevent mushrooms from growing in your lawn:

Remove Mushrooms Manually

When you spot mushrooms, dig them up with a trowel or shovel and put them into a bag immediately. Do not mow over them or dispose of them in your compost pile, as this will scatter the spores and potentially lead to more mushrooms.

Improve Drainage and Sunlight

Mushrooms thrive in damp and shady conditions. Address any drainage issues by aerating your lawn and reducing compacted soil and a thick thatch layer. If trees are shading your lawn, trim them to allow more sunlight to reach the grass.

Apply Fertilizer

Use a nitrogen fertilizer to speed up the decomposition of organic material that mushrooms feed on. This will also promote new grass growth and prevent mushroom growth.

Use Commercial Fungicides

While fungicides don't directly kill mushrooms, they can be used to treat and prevent the underlying fungal growth. Commercial fungicides such as azoxystrobin or flutolanil can be applied to treat large outbreaks, but this must be done by a professional and may need to be repeated. Jonathan Green Lawn Fungus Control is another broad-spectrum granular grass fungicide that can be used preventatively or to stop the spread of fungal diseases.

It's important to note that a healthy lawn is less likely to grow mushrooms, so proper lawn maintenance, mowing, and watering are essential to deterring mushroom growth.

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