By Pam Charbonneau, OMAFRA Turfgrass Specialist
Insects
Mid-June is the start of adult European chafer flights in southwestern Ontario. These flights usually last until mid-July and peak around Canada Day. I advise that turf managers go out at dusk at times during this window and observe the adult flights. If the adult flights are heavy, and there is a history of European chafer damage in the area, I would recommend a preventative application of Merit. Japanese beetle adults do not usually fly until July. Optimum control is achieved when Merit is watered in within 24 hours. Merit is registered for use in Ontario on European chafer and Japanese beetle grubs. It can be applied only once per season.
Another insect to look for in the month of June is turfgrass scale. Turfgrass scale crawlers are young nymphs of the turfgrass scale. They are bright red in colour and the size of the head of a pin. They usually emerge in mid to late June. They are most noticeable when you walk through the turf wearing light coloured shoes. If there are high enough numbers, they will turn your shoes a reddish tinge. People, wind, pets, etc. will spread the crawlers to new turf areas. Once they reach new turf areas, they will settle in the crowns of the turfgrass plants and begin feeding by sucking the juices out of the crowns. There is now insecticide registered for control for turfgrass scale in Ontario. They are considered a minor pest, but one to be aware of nonetheless.
Disease
When June is wet, watch out for the disease Helminthosporium leaf spot. The leaf spot stage of this disease is rarely a problem. If the disease moves into the "melting out" phase, there can be some turf loss. The best way to treat the "melting out" phase is to raise the mowing height and fertilize lightly. When June conditions are extremely dry, especially after a cool, wet May, necrotic ring spot symptoms will likely be evident. Cultural controls for necrotic ring spot are as follows:
- Control thatch
- Use either slow release fertilizers or fertilize lightly and frequently
- Irrigate deeply and infrequently, coupled with light irrigation in mid day to take stress off of turfgrass roots
- Core aerate to encourage deep rooting and overseed with perennial ryegrass where symptoms persist.
Weeds
In early June, there is often still time for post-emergence broadleaf herbicide applications. These herbicide applications work best when weed growth is active. Be careful with herbicide applications during hot weather. It is not recommended to apply herbicides when the daytime temperature gets much over 27°C. By the end of June, scouting for crabgrass can often be done to determine if a post-emergence crabgrass treatment is necessary. Dimension can be used for early post emergence control of crabgrass. Use Acclaim for multi-tillering crabgrass control.
Aeration and fertilization
June is a good time to apply at least one application of fertilizer. For turf that received a late season fall fertilizer treatment, the first spring fertilizer treatment can go down as late as late May or early June. For turf that received an early spring fertilizer treatment, the second fertilizer treatment can be applied by mid to late June. June is also a good time to core aerate. Core aeration requires that the soils are neither too wet nor too dry. It is also advisable to have 30 good growing days after aeration before the heat of the summer arrives.
OMAFRA Publication 384, Turfgrass Management
Recommendations, 2001 Supplement now available!
Do you want to know what insecticides are registered in Ontario for European chafer grubs? Have you wondered what is the best species of turf for shady sites? Do you need up-to-date contact information for all the turf seed companies in Ontario? Want to know all the new fungicides registered for use on turf? If the answer to these questions is yes, you need the 2000 Turfgr
