Most grubs have an annual life cycle so it is important to be on guard against them. There is no way to tell if you will develop a problem with lawn grubs from year to year since it is a matter of where the adult decides to lay her eggs. If grubs have been a problem on your lawn in the past, chances are that you should take a proactive approach. The only form of grub control which is allowed by Health Canada and the Ministry of the Environment at this time is beneficial nematodes. All forms of synthetic chemical grub control are banned for sale and use in Ontario. Unlike synthetic forms of grub control that could be applied at any stage of the grubs life cycle, nematodes need to be applied as a preventive when the grubs have just hatched. The grubs skin needs to be soft so the nematodes can penetrate the skin to kill them. The best time to apply white grub control is mid-august to mid-October depending on weather. Other species of grubs are treated at different times. For optimum control, a spring and late summer treatment is recommended. Since the Niagara region has several grub species, it is important to constantly monitor the lawn, properly identify the pest and treat at the most effective time.
It is not possible to treat surface insects until they are present so it is important to keep a watchful eye on your lawn. A lawn that is watered on a regular basis should stay green. If your lawn starts to show discoloured areas in spite of enough water, chances are that you have an insect problem. If over the course of 3 days, you have watered a section of concern and you do not see any recovery, you need to have the lawn assessed. Never allow more than 3 days to pass without addressing the problem, if you don’t address it, you could potentially lose all or part of your lawn in 3 to 4 weeks.