skip to content

Grubs and Nematodes

The Who, What, Where, When and How?

Most of us who have owned a lawn are familiar with White Grubs.  These white ‘c’ shaped creatures are destructive lawn pests that chew the roots of grass plants causing large irregular brown patches. This damage is evident in early spring as well as late summer.  It’s odd to think that so much damage can be achieved by such a small baby (yes, I said baby.  White Grubs after all, are the babies of European Chafer, Japanese Beetles and June Beetles…so cute aren’t they?).  Now that we’ve identified the problem, let’s figure out a solution!  

You may or may not be aware of the Pesticide Ban that occurred for Ontario in April of last year.  This Ban put a stop to the sales and use of all chemical pesticides on the residential level.  This means that all the nukem’ type chemicals that did a fabulous job of obliterating all insect life in the lawn are no longer available.  To some this is tragic news but to others this was a necessary step to helping our planet.  There is good news for grub control which comes in the form of a parasite called Nematodes.  There are millions of types of nematodes existing all over the world, some good and some bad.  Scientists were able to isolate and culture some very beneficial strains that actually seek, ambush and most importantly, destroy white grubs and other bothersome lawn and garden pests.   The best part is that these nematodes are perfectly safe for everybody (unless of course you are a grub!) and can be easily applied to eradicate white grubs.

How they work:

Nematodes as mentioned are a parasite.  There are two species that are cultured for lawn insect control; Steinernema and Heterorhabditis. They enter the grub and infect it with a bacterium that kills the grub in a mere 48hours.   The nematodes then reproduce creating an army that continues the cycle of total grub annihilation.   What we have here is a living pesticide that multiplies for free!


Nematodes are living therefore they need to be stored in the fridge until time of use.  This means do not let them bake in the hot car while you go grocery shopping!  Nematodes are most commonly sold in a box that contains a sponge that is sealed in plastic.  There are millions of these microscopic guys living in this sponge.  Application can be achieved in two ways.  One requires diluting the nematodes in a bucket of warm water and spraying them on the lawn or the second (and easier) requires investing in a hose end sprayer that is set to the recommended dilution rate.   Make sure the ground is moist before applying and stays moist for a few days afterwards.  Always follow package directions.

Prime time for applying is in early spring (post frost warnings) and then again at the end of August through September.  These are the active feeding windows for White Grubs.  They are easiest to kill when they are young so watch for the damage signs and apply immediately for faster knock down. 

For more information visit  or stop by Pathways to Perennials for a closeup view or application demo. We sell nematodes and many other natural insect controls that are easy to use, fun to watch and simple to learn about. Happy to see you soon.

Landscape Design

Book a Complimentary Consultation

Speaking Engagements

Engaging and Informative Presentations for Groups