How to Maintain a Healthy Lawn Free of Grubs

Lawn Care Grubs: A Complete Guide to Safeguarding Your Lawn from These Subterranean Pests

At one point or another, any homeowner proud of his or her lawn-social gathering, barbecue, or simple family bonding-sees the yard slowly consumed by unsightly, brown, dying patches. Though a lawn may deteriorate for several reasons, one culprit that most of the time remains unnoticed is beneath the surface: grubs.

These small, C-shaped larvae may seem harmless, but they can cause devastation in a lawn when their appetite for grass roots is unhindered.

This article will detail what you need to know about lawn care grubs: what they are, how to identify them, and most importantly, how to control them from destroying your lawn.

What Are Lawn Grubs?

White grubs are simply lawn insect, also referred to as white grubs. These insects hatch from the larvae of several different types of beetles, but the most commonly found beetles include Japanese beetles, June bugs, and European chafers. Although the species type may vary based on your location, the damage that is caused will be very similar.

Grubs have soft, white bodies with brown heads, and usually assume the letter “C” shape. They occur just beneath the soil surface, where they feed on grass roots and other plants.

The greatest amount of damage occurs from late summer through early fall, when the grubs are actively feeding and building up their fat reserves for overwintering as adult beetles.

Although a few grubs here and there may not do substantial damage, a large population of these insects can devastate a lawn in quick time because they cut the roots of grass, thereby making it hard for the turf to absorb water and nutrients.

Lifecycle of Lawn Grubs

Understanding the life cycle of grubs is essential for their effective management or control. Grubs have four major life stages: egg, larva, pupa, and adult. Let’s look closer at each stage:

1. Egg Stage: During late spring or at the beginning of summer, female beetles lay their eggs in the soil. These eggs are white and spherical while being quite small in size, hence hardly seen without digging into the soil.

Larval Stage: Upon emergence, the larvae  begin to feed on the grass roots; this is usually considered the most injurious stage of its life cycle. Generally, grubs would feed during late summer and early fall before they move deeper into the soil to overwinter.

Pupal Stage: In the spring, the grubs enter the pupal stage, where they undergo metamorphosis to become adults.

4. Adult Stage: Beginning in late spring and continuing into early summer, adult beetles emerge from the soil and mate; they then restart the cycle by laying eggs in the soil.

The most Lawn damage is caused during the larval stage of grubs when they are actively feeding on grass roots.

This damage often becomes apparent in late summer or early fall, when brown patches of dead grass start to appear.

Identifying Grub Damage in Your Lawn

Recognizing early signs of grub damage can prevent a small problem from developing into a full-blown infestation. Here are some common signs indicating your lawn may be suffering from grub damage:

1. Brown, Patchy Spots: One of the most easily recognizable symptoms of grubs is brown, dead, patchy spots in grass areas. These usually are irregular and can be gradually enlarged. The grass over these areas will feel very spongy or soft because the roots have been destroyed or completely severed by the grubs.

2. Peeling of Turf: This is a classic symptom of grub injury in turf-the capability of peeling back or lifting off the turf as if it were lifting a carpet-is extremely easy due to grubs having consumed all the roots, leaving nothing to anchor the turf in place.

3. Increased Wildlife Activity: If you begin to notice wildlife, like birds, raccoons, skunks, or moles digging in your lawn, there’s likely grubs present. Animals are natural predators of grubs and will tear up your lawn to get them.

Presence of Grubs: If you feel that your grassy area is damaged due to grubs, you can dig a small portion of your area – about one square foot – and inspect the soil. If you find more than five to ten grubs in a small area, they are probably causing significant damage.

Why Are Grubs So Harmful to Lawns?

Grubs are very detrimental to a lawn because of their feeding habit. They actually feed on the roots of the grass, which impairs the potential of the plant to take up water and nutrients.

Underdeveloped roots lead to weakening of the grass and, to some extent, its death, resulting in ugly brown spots that hardly regain life.

Although most lawns will not show actual signs of damage with a few grubs present, a large grub population may cause major damage.

The lawn may suffer to such an extent that major portions have to be either reseeded or replaced altogether.

Prevention of Lawn Grub Infestations

The best way to control grubs is to prevent them from being a problem in the first place. Here are some effective grub prevention strategies that can be enacted.

1. Keep Your Lawn Healthy

A healthy lawn is more likely to hold its own against grubs. Here’s how to make sure your lawn is at its best:

Proper Watering: Grubs like to lay their eggs in dry soil: thus, proper watering of the lawn during late spring and early summer can discourage beetles from laying their eggs in it. You can try to achieve about an inch of water a week through deep and infrequent watering sessions.

Mowing: Keep your lawn at the correct mowing height for the type of grass. Taller grass shades the soil, keeps it moist, and is less attractive to beetles.

Fertilizing: A well-fed lawn can resist invasion by insects and diseases. Needless to say, fertilize your lawn accordingly with a balanced fertilizer in spring then again in fall.

Aeration: Aerating the lawn this fall can help avoid grubs’ infestation since it allows air, water, and nutrients to effectively penetrate the soil, thereby strengthening grass roots and thus making it hard for grubs to cause serious damage.

2. Beneficial Nematodes

Beneficial nematodes are microscopic worms applied to your lawn for natural control of grubs. These nematodes enter into the bodies of grubs and release bacteria that ultimately kill them.

While nematodes are harmless to your lawn, pets, and other useful insects, they are lethal to grubs and target them very effectively.

The best timing of the application is early fall, when the grubs are most active.

Be cautious with the application procedure in order to enhance the effectiveness of your nematodes, since generally they need favorable conditions to survive and be effective in your lawn.

3. Milky Spore Disease

Milky spore is a bacterial disease specific to Japanese beetle grubs. Grubs that ingest the spores are infected and die releasing more spores into the soil to begin the cycle again.

While milky spore may take a few years to establish in your lawn, it does provide some long-term control of Japanese beetle grubs with no affect on other insects or plants.

It’s a good environmentally friendly method of grub control, particularly when you have a recurring problem.

Controlling Grubs in an Infested Lawn

The sooner you take action, the less overall damage you will have, if indeed you have a grub problem. The following are some common methods of controlling a grub infestation:

1. Chemical Insecticides

Application of chemical insecticides will help in effectively controlling grubs, especially under severe infestations. Insecticides commonly used for the control of grubs are basically of two kinds:

Preventive insecticides are products applied to the lawn prior to the hatch of grubs, which occurs sometime from late spring into early summer. Products control grubs when they hatch from eggs and begin to feed on grass roots. Preventive insecticides are a good fit if you have had grub problems in the past and want to prevent them from returning.

Curative insecticides are used to kill grubs already in your lawn and work best in late summer or early fall when grubs are actively feeding.

However, curative insecticides are sometimes not as effective once grubs have been allowed to cause extensive lawn damage.

In the use of chemical insecticides, one must be very cautious and apply the dose as instructed by the manufacturer for safety and effectiveness.

At the same time, one should have a comprehensive knowledge of the actual effect on beneficial insects and the environment.

2. Hand-Picking of Grubs

When the grubs are at a minimal level, these can be dug out and manually removed. Usually, this is manpower-intensive and not suitable for large-scale inroads. It serves only to reduce the grub population in very small areas.

3. Watering After Treatment

After any treatment for grubs-chemical or biological-it is important to water your lawn well. Watering helps move the treatment down into the soil where the grubs are feeding and assists in evenly distributing the product.

Repairing GrubDamaged Lawns

It is now time to fix the damage once you have faced your grub problem. The following are some steps, depending on the intensity of the damage:

1. Rake and Remove Dead Grass

You should rake away dead grass and debris from such areas. This will expose the soil, and you can then reseed or lay down new sod.

2. Aerate the Soil

If there has been extensive damage to your lawn, aerating the soil will help with better water and nutrient infiltration. This will be a big help for the new grass to establish a strong rooting system and recover more quickly.

3. Reseeding

Once the damaged areas are clearly cleaned out, reseed the lawn with