Grubs in lawn

(Question)

My lawn has few yellowish patch. Some one told me that I have grubs in my lawn, they just trade my neighbor’s lawn, and I should do the same treatment. My question is how to find out the patch is caused by grubs. If yes, what kind of product available in Toronto can control the grubs. Thanks.

(Answer)

Just on the edge of the yellow area and healthy grass, take a shovel and skim the grass about 1 inch below the surface, then peel back the grass. If there are grubs, you’ll see them. A natural method to eliminate white grubs is beneficial nematodes. Nematodes search through the soil, locating a host and then enter through natural body openings. A natural bacterium is released that is fatal only to the insect, which dies within 24 to 48 hours. The nematodes reproduce and continue to eliminate grubs as long as soil moisture conditions allow (6 to 8 weeks).

Application should be done when soil temperatures are above 10°C, preferably above 15°C. The lawn must be kept moist for two weeks after application. The solution must be able to penetrate to the root zone area, thus a properly dethatched lawn is advisable. There are no harmful residues left in soil that could contaminate water supplies.  If renovating a turf area after a severe infestation, consider using new cultivars that are resistant to infestations of grubs.

The Toronto Master Gardeners have created a detailed Gardening Guide which may help Lawn Alternatives and Organic Care of Groundcovers.