Grub damage vs fungus issues can be a bit perplexing since both have similar symptoms, especially when you’re very particular about lawn care.

Grub Damage vs Fungus

While it can be worrying for new gardeners, identifying it will be easier once you go through this guide.

We discuss the differences between these two types of lawn problems and identify the symptoms of each.

Symptoms Grub Damage  Fungal Damage 
Color The presence of dark or brown spots of grasses forming in the lawn Signs of white, grey, or black powdery strings in the vicinity
Lawn An unusual increase in the number of animal activities in your lawn or garden Roots and stems of your grass have spots of red, orange, purple, grey, or black colors
Grass Resistance It is quite easy to lift the grass right up from the ground The grass resists when pulled or tugged away from the soil
Soil Appearance The soil beneath the brown patches tend to be springy and spongy The general infected area looks wet, slimy, and greasy
Grass Appearance The dead patches of grass are in warm, sunny spots Blades of grass start to lose color or turn yellow

What Are the Main Differences Between Grub Damage and Fungus?

The main differences between grub damage and fungus is that grub damage can be seen when your lawn has unusual patches of brown areas that tend to be in well-lit areas, while fungal problems typically show up as powdery patches of white, grey, red, orange, purple, or black.

What Are the Symptoms of Grub Damage?

The symptoms of grub damage include several patches of dark brown grass, an increase of animal activity that can be seen in your yard, grass lifts easily from the ground, springy and spongy soil, and dead grass in warm and sunny spots.

First, we need to understand what a grub is. A grub is a larva, or the baby form, of different types of scarab beetles. The larva is pale, fat, and worm-like in appearance. As a result, it goes by two of its most common names — the white grub and the lawn grub.

These larvae feed on the thatch and roots of turfgrass. Most grub species live for a year before maturing into beetles. On the other hand, certain species can have their larvae remain in this stage for up to two or three years before turning into a beetle. To further explore the extent of their damage to garden lawns, let’s look at each in detail.

– Several Patches of Dark Brown Grass

When areas with brown grass appear on your lawn, you can start suspecting the garden grub as the main culprit. Since the grub feasts on the roots of the grass, it can leave your turf with spots of dead grass.

– Increase of Animal Activity in Your Yard

The garden grub is a favorite snack for many wildlife such as birds, skunks, and raccoons. If you notice more of these animals out in your yard and flying, sniffing, or scurrying about your lawn, you just might have a problem with grub infestation.

– Grass Lifts Easily From the Ground

Since the garden grub hordes have munched the roots of the grass away, they end up as clumps of dead leaf blades. As a result, the rootless patch of dead grass gives way when pulled from the ground. To test this, simply tug at the patch of brown grass in your lawn to see if it gives way.

Grub Damage Characteristics

– Springy and Spongy Soil

Usually, the garden grub will leave the soil soft and springy as it eats away at the roots of your grass. Since the roots are gone, the ground will remain mostly damp. This adds to the spongy texture of the soil that the garden grub has caused.

– The Dead Grass Are in Warm Sunny Spots

The garden grub loves to live in soil that gets exposed to the sun. As the soil warms up, the temperature encourages the garden grub to eat and grow. Consequently, your lawn suffers from grub damage with patches of brown dead grass.

What causes the white grub infestation in your garden? There are basically three reasons that cause the garden grub to grow in numbers and quickly overtake your lawn. The first factor is when the soil is overwatered and overly wet. The second factor is growing or cutting grass that is too short, which results in root systems that are also short.

The deeper the roots, the less damage that the garden grub can cause. The third factor is when the lawn has been overly aerated, causing too many patches of bare earth for beetles and other insects to lay their eggs in.

What Are the Symptoms of Fungus Infestation in Your Lawn?

The symptoms of fungus infestation in your lawn include white, gray, or black powdery strings around the garden, the roots and stems of grass are covered in colored spots, grass resists when pulled, and the area looks wet, slimy, and greasy.

Lawn fungus are often present in many lawns although they sometimes do not damage them right away. Fungal spores only cause lawn disease when the opportunity strikes, such as overly wet conditions and the presence of organic matter.

Generally, fungi are beneficial to many gardens since they decompose most organic matter. However, they can wreak havoc when there is excessive heat and humidity, which can cause them to reproduce and multiply unchecked.

They attack by attaching their microscopic feeder tubes to plants, which include turfgrass. Once they latch on, they quickly suck the life out of the grass. Let’s look at the symptoms in detail.

– White, Grey, or Black Powdery Strings

These are the visual manifestations of fungal problems in infected lawns. The powdery strings are fungal spores that eat and spread all over the lawn. As a result, infected patches of your lawn will look like they are covered with fine powder.

– Roots and Stems of Grass Are Covered in Colored Spots

Another telltale sign of fungal infections is when parts of your grass have colored spots. They can come in various colors, such as red, orange, purple, grey, and black. Usually, these spots are on the roots and stems of the grass.

– Grass Resists When Pulled

Fungi feed on the plant itself but does not do much damage to the roots. As a result, the whole  plant remains intact but sickly. Under this condition, the patch of grass will resist when pulled, which contrasts highly with the damage caused by the garden grub.

Fungal Damage Characteristics

– Grass Area Looks Wet, Slimy, and Greasy

Fungi thrive in wet and moist areas, which makes them spread even more. Since this is their ideal growing condition, infected grass patches will look wet, slimy, and greasy due to their presence.

– Leaf Discolorations

When fungal infections attack your lawn, they intercept the grass’s absorption of essential nutrients. As a result, your grass will start to thin out and eventually lose its vibrant green colors. Finally, infected turfgrass will turn yellow.

What causes the fungal problems in your lawn? Fungal issues can be easily brought about by periods of droughts, overwatering, wrong fertilizer use, too much fertilizer, overly compacted soil, improper mowing, and high levels of temperature and humidity.


A brown patch can definitely cause concern and it may be caused by a failure to do proper grub control. When encountering a potential grub problem, you can administer pest control by applying neem oil or milky spore as well as introducing beneficial nematodes that prey on the grub. This will ensure that they remain under control or even disappear.

A dollar spot is one of the most common symptoms of fungal infections that are visible signs of lawn disease. To ensure proper lawn care, you can always pick up some grub and fungus killer from garden centers. Simply follow the instructions on the labels and your lawn should come back healthier than ever before.

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