Grubs are the most feared and over hyped lawn problem existing for homeowners. Beginning in spring the chemical lawn fertilizer companies set off the alarm via advertising on how to get rid of the unattractive dweller.
“How do I prevent grubs?” you ask. Control is easy by following a simple organic lawn care program.
“You’ve Got Grubs!!”
The scarab is part of soil life and our ecosystem. Their larva will be present in even the best soil. It does not mean they all need to be dead. The soil food web is a complex part of nature. Balance should be the ultimate goal. Once one particular member of the food web begins to dominate issues will arise.
Killing Lawn Grubs With Chemicals Harm
Beneficial Insects In Your Soil
If there are more that 10 – 15 per square foot of turf, lawn problems may arise. Generally, if beetle damage is observed, it is too late to reverse it. Prevention is the best remedy. And it’s a lot easier, cheaper and safer than spreading insecticides of your grass every year.
A few white grub facts:
- Most species in the family Scarabaeidae
- Range in size of 1/4 to 1 inch
- They chew with their mouths open
- Adults do not feed on grass
- They have 3 (instars) larva stages
- Are identified by the raster (front of the anus)
The larva second and third stage is when most of their turf feeding happens. Most of the lawn damage will happen in the heat of the summer generally in August and September. Ample moisture compounds the grub problems.
Signs of Grub Damage
Larva in their third stage produce most of the turf damage. They are present at the soil surface from August and September and move down below the frost line during winter. The following May and June they are present again at the surface before becoming adults.
Early signs of damage can be confused with many other turf issues such as disease, drought or other insect damage. A thinning and yellowing appearance of the turf becomes obvious.
A distinct characteristic of latter stages of grub damage becomes evident. One would be able to pull the damaged sod up like a piece of carpet. You’ll know. You should be able to remove the top layer of sod easily by hand or just by kicking it.
When checking for grubs in your lawn there is no need to look under the damaged dismantled sod. Look where the damaged grass meets the relatively healthy looking lawn.
That’s where the fresh food is for them
It is also where you would apply an insecticide of your lawn to prevent complete annihilation of your green lawn. No need to spread the insect killer everywhere. Use it sparingly and put a little effort into finding where the populations are. No need for a complete genocide of all the insects and earthworms in your soil.
The preceding paragraph is one of the rare times I would recommend using an insecticide. If the damage potential both financially and aesthetically outweighs the environmental concerns then minimum and careful application would be acceptable.
A Few Types of Lawn Beetles
Japanese Beetle – Popillia japonica
- Larva can cause much turf damage
- Causes severe damage as adults on foliage and flowers
- V-shaped raster
European Chafer – Rhizotrogus majalis
- Causes severe turf damage
- Feeds little in adult stage
- Y-shaped raster
Oriental Beetle – Anomola orientalis
- Many times found dead in a swimming pool
- Will eat other plants besides turf when larva
- Parallel raster
How to Get Rid of Lawn Grubs
Similar to just about every turf grass problem, the number one control measure should be having a healthy thick lawn. Following our other pages on this website should guide you in the right direction.
There are some wonderful organic preventive measures available today. Most of them need only be applied for a couple of years and then you’re good for probably at least 10 years to come.
Identification of which type of lawn insect that is problematic is your first step. No sense is wasting money on a cure if it isn’t going to target the right species.
Controlling Japanese beetle is probably the easiest of all lawn beetles. Milky disease is a very effective preventive of Japanese beetle damage. It is commercially available as Milky Spore and can be found at our grubs killer organic products store.
Applied twice the first season, the spore enters the larva when they feed on the lawn’s roots. As the larva dies millions of spores are released into the soil. The spores begin to multiply and continue to spread throughout the entire soil and lawn area.
After 3 – 4 applications over a two-year period you should have no worries about the Japanese beetle’s wrath that it’s reputation brings. A lawn that’s chemical free and no expensive insecticides after a couple of years.
Of course, the traditional “step program” big companies do not want you to know that. As we all know, there is no money in a cure.
Parasitic nematodes as a control, is certainly making advances. Unfortunately there is no species to control all the different white grubs. Some grubs are more susceptible to nematodes than others.
Different nematodes are necessary to defend different lawn beetles
Nematodes are generally very effective against the Japanese beetle. Heterorhabditits bacteriophora would be the choice as a preventive against Japanese beetle.
Heterorhabditits bacteriophora among other nematodes needed to kill grubs are available at our
organic lawn care products store.
Other varieties of scarabs are less susceptible to the damage nematodes provide although research is certainly making progress.
Regardless of which nematodes you use to fight lawn grubs,there are basic fundamentals to follow
- Nematodes are microscopic worms
- All are applied in a liquid spray
- Timing of soil temperature and larva stage are important
- Should be applied mid-August to early September
- Nematodes are susceptible to UV radiation
- Apply early morning, late afternoon or when cloudy
- Needs to be refrigerated until use
As with Milky Spore, applications of insect parasitic nematodes after a couple of years stay abundant in the soil.
Many times I’ll make two applications of Milky Spore and an application of nematodes per year for two years. I’ve had a good deal of success with this schedule. Then I have a problem free lawn for a decade to come. And a very happy customer.
It saves money, effort and all accomplished more effectively than a bag of synthetic chemicals can provide. I also know I’m no longer getting hoodwinked by the big fertilizer and pesticide suppliers of the world anymore.