Japanese beetles, June Beetles, and European chafers seem to spawn out of nowhere; however, you've probably already seen them long before they can start to fly. These insects start out as lawn grubs - those squishy white insects that you find below the grass roots.
The best way to prevent beetle damage is to eliminate them in grub form. They have not yet developed the thick exoskeleton that makes them impervious to bee-safe insecticides. Additionally, the treatment for grub prevention is easy and only needs to be addressed once a year!
How do I know if I have grubs?
One of the most obvious indicators of grubs is that animals like skunks, dogs, and birds will dig through the grass to eat the grubs. If you notice patches of brown grass that feel spongy and can be easily pulled apart, it is likely grubs that are damaging the roots of the lawn. You can manually check to see if you have an infestation by using a shovel to cut and lift a section of grass - at least a square foot - to look for grubs under the root system. The Government of Canada states that if you are able to find more than 8 to 10 grubs per square foot, you likely have a serious infestation.
Depending on what type of grub is in your lawn, you will notice the damage at different times of the year. This is because June beetles, European chafers and Japanese beetles have different lifecycles. June beetles take 3 years to mature from grub to beetle, while European chafers and Japanese beetles only take a year to transition. Take a look at the chart below to get an idea about when grubs are the most voracious in your lawn.
When can I treat my lawn for grubs?
The best time to treat your lawn for grubs is in the late spring or summer to fall. Grubs are the most susceptible when they are the most active as they are closer to the grass roots and more likely to be effective by both chemical insecticides and natural nematodes.
Method 1: Natural Beneficial Nematodes
If you have dogs, cats, or small children, beneficial nematodes is the BEST option for safe application of grub treatments. Beneficial nematodes are easy to apply and are pet safe.
Nematodes are microscopic worms that are native to Canada. Nematodes are sprayed onto the lawn using a hose-end sprayer and make their way into the grubs as a host. Once they have attached, they infect the grubs with a bacterium that breaks down the grub's tissues. Once the grubs have died, the nematodes reproduce and search for a new grub host. The bacterium that infects the grubs is completely safe for earthworms, beneficial pollinators, and burrowing animals.
Gardeners interested in using beneficial nematodes do need a hose and a hose end sprayer. In ideal conditions, apply nematodes before a couple days of rain, otherwise you will need to keep the grass moist manually (using a hose or irrigation) to help the nematodes flush from the grass blades and into the soil.
We sell nematodes provided by NIC, an Ontario company. They have lots of great additional information on Grub Control, as well as this super useful video on how to apply the beneficial nematodes that we sell!
If you have any questions about beneficial nematodes, reach out to us and we would be happy to help!
Method 2: Chemical Grub B Gon
IMPORTANT: This option is not suitable for those with outdoor pets or small children within 8 hours of the application.
Grub B Gon is a granular chemical pesticide that is best applied in early August to the lawn. Grub B Gon is an approved chemical pesticide that "disrupts the nervous system of the grubs, causing them to become paralyzed and die". Grub B Gon is sprinkled onto the lawn before a rainfall (or you can use manual irrigation) to penetrate the soil level and become accessible to the voracious grubs.
Grub B Gon is advertised as a safe chemical for bees and other beneficial pollinators.
When will I see the results?
By applying grub control product, you give your lawn a second lease on life. If applied appropriately in the summer, you will see your lawns regenerate in the fall and notice a significant decrease of damage in the spring.
Remember that beetles are flying insects. If you apply grub control but your neighbours don't, you may still see beetle activity. The more people who are informed and practice grub control, the better your community can control the beetle population.
How often do I need to apply the product?
The first year you apply grub control, you should target the two feeding seasons: Spring and fall. If your first application is in August, it would be beneficial to apply again in early May the next season. After your first year, it only needs to be applied once in August.