Grubs are the larvae of different kinds of beetles: Japanese beetles, European chafers or June bugs. They are C-shaped, milky white in colour, with a brown head and six prominent legs. Since their life cycle only lasts one year, these unpopular grubs are very prolific...
Towards the end of June or the beginning of July, when the rose bushes are in bloom, the daylilies are dazzling and the raspberry bushes are beginning to produce, adult chafers, Japanese beetles and others make their entrance.
During the day, they eat the leaves of your plants, and in the evening, they lay their eggs in your lawn.
When the eggs hatch, the larvae penetrate the soil and begin feeding on the grass roots. For weeks... And since they survive the winter, the damage continues in the spring.
How do I know if I have white grubs in my lawn?
In early spring, birds, especially starlings, flock to your lawn, abandoning their feeders to dig their beaks in between the blades of grass. You blame them for this devastation... until you notice skunks and raccoons digging in the same spot.
In fact, the real culprits are white grubs. After feeding on your lawn, they become a delicacy many animals love to feast on.
You only have to turn over the soil to see them beneath your wretched lawn. While their presence is normal, finding more than five per square foot is a problem.
White grubs destroy grass by feeding on its roots. The presence of yellowed patches of grass, which you can lift like a carpet, is a telltale sign of a grub infestation. Damage is usually noticed around the end of July or the beginning of August, especially in sunny, well-watered areas.
PRO TIP
You can replace the patches of grass torn up by skunks and raccoons. By applying firm pressure and watering sufficiently, the grass has a good chance of recovering. If the damage is too extensive, you will need to repair the lawn by adding soil and compost, and then overseed.
How to get rid of white grubs?
If you're dealing with a white grub infestation and don't want to use chemical pesticides, why not turn to Mother Nature?
Nematodes are small, microscopic, beneficial worms. They need to be mixed with water to wake up and are then sprayed on the lawn. Once in the soil, they seek out a host, usually a grub. Nematodes carry a pathogen that they inject into the host grubs.
This pathogen multiplies and kills the grubs within a day or two. The nematodes then lay their eggs on the dead grubs. The new nematodes will hatch and seek out more grubs. Mother Nature to the rescue!
This solution is safe for the health of humans, pets and the environment.
When to treat for white grubs?
Nematodes can be used in the spring, from late April to mid-June, once the ground has thawed. At this time of year, the grubs that have overwintered deeper in the soil come to the surface to feed on your lawn.
In August, the eggs have hatched, and the grubs begin feeding on the grass roots. It is the best time to eliminate them, as they are small and very active on the surface.
Since they will burrow deep into the soil before the first frost, treatment can be continued until late September or early October, depending on the region (soil temperature should be between 10 °C and 30 °C).
If the infestation is severe, you may need to repeat the treatment in September after treating in August. After September and during spring, white grubs are much more difficult to control.
To learn how to treat using nematodes, check out our Wilson GRUB OUT Nematodes for white grubs.
PRO TIP
It is recommended to apply nematodes when the lawn is wet. Apply after a rain event or water the lawn before application.
7 tips to prevent white grub infestations
- Make sure you have a thick, healthy lawn, and rich, balanced soil.
- Keep your lawn 8 to 10 cm long. Beetles prefer to lay their eggs in short lawns!
- Aerate the soil in spring.
- Water less often but deeply, preferably in the morning. The grass will develop stronger roots and will be less vulnerable.
- Always use grass seed mixes. White grubs particularly like Kentucky bluegrass!
- After 8 pm during the summer, turn off outdoor lights when you can. Lights attract the beetles that are ready to mate.
- Take advantage of natural allies by attracting birds to the garden!
