August 15, 2008
By Pam Charbonneau
OMAFRA turf specialist

PamIn August you should still see some adult Japanese beetles feeding on ornamentals in and around turf. It appears that they are spreading, with many new areas of infestation. This year they emerged around the usual time and should feed through to mid-August. By all accounts, it has been a bumper year for both species of grubs in Ontario. Once we get into August, it is considered too late to get reliable results from the product Merit. The new product from Dupont, chlorantraniliprole (DPX-E2y45 20 SC insecticide) may be applied until late August for European chafer and Japanese beetle grub control. This is also the timing for applying nematodes for grub control.

Leatherjackets will pupate in the later half of August in preparation for adult emergence in the middle of September. This fall, as with last fall, we hope to go to many areas of the province to capture live adult crane flies. There is a new species (Tipula olerace) that has been identified in Ontario and we are interested to know how widespread it has become. Both Tipula paludosa and Tipula oleracea emerge in September.


Rust began very early this year. It could possibly cause some turf thinning this fall if conditions continue to be favourable for this disease. Rust is caused by stress, as well as fluctuating warm, wet conditions and hot and dry conditions. The symptoms are chlorotic spots of leaves. Reddish orange spores are produced mainly on the underside of the leaves. The rust coloured spores rub off on shoes and equipment. This disease is usually managed with nitrogen fertilizer, but if conditions for rust development persist through the late summer and into the early fall it can severely thin a stand of perennial ryegrass and Kentucky bluegrass.

Fertility and cultural practices

Mid-August is a good time to fertilize turf. At this time the temperatures are usually ideal for the turf to recover from damage that occurred during the summer. This is especially true if July has been a hot, dry month. This should be the first part of your two-part turf winterizing program, with the second application in late October to early November. Our research results show that adequate fertility can go a long way in suppressing weeds. August is also a month when we usually get adequate rainfall for turf growth. Because turf is usually growing quite well in August, it is also a good time to core aerate any lawns with thatch problems. Mid-August to mid-September is also the ideal window for overseeding damaged turf areas or establishing new turf areas. Timely rains ensure good germination and establishment at this time of the year.

August is also a good time to scout for crabgrass-infested areas. These areas can then be treated with corn gluten meal, which will be the only product allowed for pre-emergence crabgrass control in the spring of 2009 after the provincial pesticide ban comes into effect.

GTI Turf Research Field Day

The GTI Turf Research Field Day will take place on Thurs., Aug. 21, 2008. Current areas of research that you can learn about include disease and insect biology and control, pesticide alternatives, evaluation of turf varieties, velvet bentgrass establishment and management, thatch management, irrigation scheduling, sportsfield overseeding and grassland ecology, to name a few. The program runs from 8:30 to 1:00, with lunch included. For registration details, please visit the GTI website at

Sports Turf Association Field Day

The Sports Turf Association’s Annual Field Day is Thurs., Sept. 11, 2008, in Brampton, Ont. The Field Day Committee is in the midst of applying the finishing touches to the event program. Check back often for all the details, as they become available at, or by contacting the STA office at (519) 763-943

Ontario Turfgrass Symposium, 2009

Please join us on Feb. 18 and 19th, 2009 at the University of Guelph for the 18th Annual Ontario Turfgrass Symposium. Mark your calendars and stay tuned for details. With the approaching provincial pesticide ban in the spring of 2009, it is crucial to learn as much as possible about the details of the ban and about potential new products and practices that can be used once the ban is enforced. At OTS, we can help you do that.
Pam Charbonneau can be reached at (519) 824-4120, ext. 52597 or by e-mail at