Why Grub Worm Preventatives Are Important

Why Grub Worm Preventatives Are Important

Maintaining a healthy lawn can be a daunting task if your lawn is being affected by insects or pests. Although most of the insects you may see around your lawn are pretty harmless, there are some, on the other hand, that can cause harm to your turf grass.

For lawn owners, one of such feared insect is the grub worm. They find their place in your soil and feed on the roots of your grass. If their numbers become too much, their activities on your lawn will eventually cause the grasses to turn brown.

Their presence on your lawn also signals an invitation for other unwelcome predators who feed on them.  When this happens, you end up with an unattractive and unhealthy lawn.

Preventing grub worms on your lawn is something you’ll want to take seriously. Because as we know, “an ounce of prevention is better than a pound of correction.”

What Are Grub Worms & Why Are Grub Worms Important?

Grub worms, lawn grubs, grubs, white grubs, or turf grubs are all common names given to this insect. But the truth is these insects aren’t actually worms. They may look like worms while still at their larval stage, but they mature to become beetles at their more adult stage.

In case you’re not sure if what you’ve seen on your lawn is a grub beetle. They are usually worm-like with an orange head and six legs. Grub worms are white in colors and C-shaped.

Grub worms come in different species, even though they all look similar at their larval stage. The most commonly found beetle in lawns is the Japanese beetle.

Life Cycle of the Grub Worm

There are more similarities than there are differences in the life cycle of the different species of grubs.

For all grubs, you’ll normally find their adults active for a few weeks during the summer period. At that time, the females will begin to lay their eggs on/under the soil. In a matter of days, those egg hatches to reveal new grub worms who begin to burrow deep.

At that point, you’ll find them feeding on plant roots. They remain in their larvae stage for several more months. Some species remain as larvae even after many years.

When winter approaches, the grubs burrow further into the soil, and during spring and fall, they return closer to the surface of the soil to feed there.

Detecting Grubs in Your Lawn

The presence of grubs in your lawn shouldn’t immediately cause you to panic. Usually, their presence wouldn’t hurt your lawn, except their population grows to become overwhelming.

Although the presence of a few grubs isn’t anything to worry about, you can determine if there is a huge infestation by digging up a portion of your lawn.

If you discover anything more than five grub worms per a quarter foot or more than fifteen worms per square foot, then it’s advisable to treat your lawn.

Since grubs most times remain deep inside the soil, it might be a little hard detecting their presence initially.

Nevertheless, there are telltale signs that would usually indicate that your lawn has a grub problem.

One is conspicuous damage to the lawn. Whenever grubs begin attacking a lawn, their activities usually causes the grasses and leaves to turn brown. Brown patches that peel off like a carpet could easily mean that grubs are having a party on your lawn.

The damage caused by grubs is usually most visible during the spring and fall seasons. This is because, at those times, the grub feeds closer to the surface of the soil.

Why Go For Grub Prevention

The safe limit for the grub population is anything less than ten grubs per square foot when the population begins to reach 10-12 grubs. The turf might not easily recover from any damage caused.

Preventative application inhibits the spread of grub infestations. If applied around late May and early June, you can be totally assured that you’ll have a grub free lawn.

The best time for treating grub is when the eggs are yet to hatch or when they are still very small and still feeding close to the surface.

Spring usually isn’t so great a time to start treatment because, at that time, they must have stopped feeding as they are usually much bigger. Applying insecticides at this time produces little or no results. At that point, there’s also a possibility that such insecticide might leach out due to rainfall.

Ways of Preventing Grub Worms

Thankfully, you do not have to live with grubs in your lawn. There are several ways of ensuring that you eradicate any problems their presence might cause. Some of which are discussed below:

#1. Stop Over-fertilizing

I’ve never really understood gardeners who knowingly over-fertilize their lawns. It really doesn’t do your lawn any good. It’s like a counter-reaction. The fertilizers stop working for the benefit of the plant and start to work against it.

Fertilizers quite alright are helpful when it comes to aiding the growth and development of plants. They do this by supplying your plants with essential nutrients that are lacking in the soil. But any more than what the plant needs can be detrimental to its health.

Grubs are usually more in lawns that are overly chemically fertilized. If you must go beyond, then switch to natural forms of fertilizers.

#2. Stop Overwatering

In almost every article about lawn care, you’ll see the issue of watering coming up. That is actually good. It goes on to show how important that part of your lawn maintenance process is.

The issue, though is, there is a way to irrigate or water properly. One common rule of thumb is to water deeply and less frequently.

Grubs tend to thrive in lawns that are watered or irrigated shallowly and too often. This is because female beetles normally prefer damp soils to lay their eggs. The hatched grubs as well also need moisture for them to grow.

Your soil doesn’t need to be soggy for your grasses to grow. Overwatering can cause you a lot when grub infestation is concerned. Watering rightly is the best way to water.

#3.  Mow Rightly

As with other lawn maintenance procedures, mowing wrongly can lead to grub problems. Female beetles tend to tilt towards lawns that are cut tightly, especially those that are well-exposed to sunlight. Laying eggs in such conditions is usually easier.

To reduce the likelihood of this occurring, it’s best to mow your lawn to about 3″ or 4″. As much as possible, don’t go lower than that.

Natural Methods for Preventing Grub Worm Infestation

#1. Neem Oil

This is a botanical pesticide that could also work as an insecticide. When applied, it inhibits the spread of the Japanese beetle as well as other species of grub worms. It is usually applied by mixing the oil in water and spraying on the areas that are being affected.

#2. Milky Spore

This is a double-edged option for treating grub infestation. The spores are first applied to the area affected. This infects the grubs as they feed. As soon as the grubs begin dying, more spores are released into the soil.

The release of additional spores acts as a preventative measure against the spread of more grub worms.


There’s a safe population when it comes to having grubs in the lawn. Once that threshold is exceeded, your beloved lawn could suffer greatly and terribly. Hence, it’s usually best to limit the spread of grubs right from the on start.

Using preventative measures could go a long way into making sure that their population is kept in check and that your lawn is not negatively affected. My advice is this, don’t wait till you have a grub problem before you begin taking preventive measures.