For any lawn enthusiast the white grub is public enemy #1! The brown patches they leave on your lawn are an eyesore that are just ugly. Fight grubs naturally with beneficial nematodes, naturally occurring microscopic worms that prey on grubs. An enemy of my enemy is my friend!

What Are They?

Beneficial Nematodes are a naturally occurring microscopic worm found around the globe in soils. Nematodes hunt and feed on soil dwelling insects by entering their body, injecting them with lethal bacteria, and feeding from their insides. The toxin usually kills the host insect within a day or two. To complete the lifecycle, they also lay their offspring in the dead grub (or other pest). There are different kinds of nematodes for targeting different turf insects, but we carry the nematodes that go after grubs!

Keeping & Using Nematodes

Nematodes are super easy to use, require very little work and no sprays! You get a whopping 10 million nematodes in an individual package. That will cover an area between 2000-3000 square feet (based on a heavy or light application rate). They are shipped in a powdery solution that mixes well in water. Be sure to keep your nematodes in the fridge (but not frozen) and apply as soon as possible for best results. They are a living insect so the longer you wait the less effective they will be (they can die if you wait too long). Do not use nematodes at are past their expiration date. You can apply them using a watering can, sprayer and hose attachment or misting system. It’s a good idea to apply your nematodes during low light periods (morning or evening are best).

It is very important that you mix and apply your nematodes quickly so they don’t ‘expire’ in the can. You want to insure the nematodes have a chance to get into the soil before the water is evaporated. If possible, you should water your lawn or apply after a light rain for best penetration. Avoid applying to over-saturated soil as nematodes will simply wash away and avoid applications when your soil temperature is below 10°C / 50°F if you’re using local, Canadian grown nematodes (15°C / 60°F for imported nematodes).

Using a hose end sprayer applicator will be applying nematodes very easy, just mix a concentration, fill your applicator and spray out nematodes until the jar is empty. Refill applicator until all your concentrated nematode solution has been applied. If you have an applicator which refills your jar as you spray mix a tea bag in with your nematode concentration. This will turn your concentration a tea colour and when the concentration is diluted clear you know you’ve run out of nematodes.

There are two periods when grubs can be targeted by nematodes, in the spring  when soil temperatures are above 10°C (often early May to early June) and again in the fall before soil gets too cold (mid-late September to mid October). During those times the insects are in a life cycle where grubs are in the soil and can be targeted. The best time is in the fall when the grubs are smaller but the most common time is in the spring. Best practice is applying during both to get best coverage and protection!

Lastly, always read the expiry date and apply before they go bad because dead nematodes don’t work and it’s very hard to see if they are alive or not. Don’t chance it, deal with them right away.

Application Video

There is a great video that shows how to apply nematodes using a hose end sprayer that is available at Heeman’s. You can watch this video here.