6 Common Lawn Diseases To Look For - Backyard Boss
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6 Common Lawn Diseases To Look For

Lawn maintenance can be a tricky thing, you want to make sure it is being cut properly, watered enough, and getting the right amount of sunlight. But even after taking care of all those things you still need to be on the lookout for lawn diseases. Lawn diseases come in many forms from spots of dead or discolored grass to rings of leaves. Most of these diseases come from fungi and can be spotted and revived, or managed if you know what to look for.

Here is a list of 6 common lawn diseases to look for and how to manage them.

Summer Patch

Dead Grass Spot Lawn
Image credit: Garrett Aitken via Canva

Summer patch is a serious lawn disease that affects the roots, stems, and crowns that have grown during the summer months. The stress of the summer heat, compacted soil, poor soil drainage, or over-mowing are all factors in summer patch. Summer patch appears as yellowish irregular or circular patches on your lawn. The infected with summer patch, the grass generally dies from the tip down to the root but if you catch it early enough, you are more likely to save your grass.

If you catch this disease before it is 2 inches of dark wilted patch then you can treat this with chemicals (Systemic fungicides) and this can be effective in saving your grass. To prevent summer patch make sure to not cut more than 2/3 the length of your grass when mowing your lawn.

Brown Patch

green grass or lawn with dead or diseased brown patch
Image credit: Justin Smith via Canva

Brown Patch is a fungus like many other lawn diseases. Brown patch is most common in very hot temperatures and it affects all types of grass and turf. It appears as a rough circular patch at first,  from 1-5 feet in size. The outside of the patch will be a darker brown and the inside will be lighter and then die off completely. Brown patch can happen in the spring, summer, and fall so you need to keep watching out for it before and after the hottest months of summer.

Managing brown patch is not very difficult. Be careful about over-watering and over-fertilizing your grass, these things tend to make it form and spread faster. If you already have this lawn disease, the easiest way to get rid of it is with a fungicide. Fungicides with fludioxonil as the active ingredient are known to work best.

Fairy Ring

fairy ring lawn disease
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Fairy ring will first appear as a dark green circle that is lush and fast growing. It will have a ring around it of dead brown grass. The biggest indicator that you have fairy rings is the puffballs or mushrooms appearing along the ring. This disease is another fungus and spreads through your lawn via spores, so you will need to be careful when tending it because the spores can get on your clothing and you could spread it to other areas.

Managing fairy ring can take a bit of work but the best way to do it is to poke a garden fork into the Fairy Ring, multiple times all over the ring and then water the areas heavily. The water will drown the disease and washes the fairy ring spores away from the grass. Fairy rings can be less visible in well-maintained lawns.

Rust Disease

close view natural wheat leaf rust disease, infestation
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Rust disease causes yellow flecks to appear on the grass, which then makes the grass begin to thin and make it more susceptible to other problems (like insect infestation) and diseases (like funguses). Rust disease generally starts to form in late summer and fall when there are conditions of low light and lower temperatures (between 70-80 degrees). Rust can live on both live and dead grass so be sure to remove the infected grass so the rest does not get infected.

When it comes to rust disease you really only need to fertilize and water your lawn as recommended. If this does not resolve things within about three weeks, you may have to use a fungicide containing propiconazole, this tends to work best on rust.

Pythium Blight

lawn disease killing grass
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Pythium blight will appear as dark, greasy-looking orange spots on your grass. If you have cool-season grass this could affect you during the hotter and humid months. This is also a fungus and will form fluff balls on your lawn. Humidity will cause this disease to spread and the spots and puffballs will start to look like cobwebs.

The best way to manage pythium blight is by using fungicides containing mefenoxam. Mefenoxam can also be used to prevent this disease if it is something you have struggled with in past seasons. If you are using it to prevent pythium blight, use it every 10-days or follow user directions.

Powdery Mildew

Powdery mildew tomato plant
Image credit: Taew Jari via shutterstock

Powdery Mildew can affect any plant including your grass. It thrives in warm, wet weather and is very easy to spot. Powdery Mildew looks like white or grey powdery spots all over your lawn. It does not have any long-lasting side effects for your lawn but it will continue to come back and it does not really look that appealing. Learn how to prevent and treat powdery mildew.

To manage this lawn disease, use fungicides designed to treat powdery mildew including; triticonazole, metconazole, triadimefon, myclobutanil, tebuconazole, and propiconazole.

Lawn Care Is Important So Look Out For These Diseases!

With everything you have going on this summer, you shouldn’t have to worry about lawn diseases. Hopefully, this list can help you identify a few of the lawn diseases that could affect you this season and help you reverse whatever they have done to your beautiful lawn.