Growing a healthy lawn means selecting the correct type of grass and using good cultural practices, including cutting, feeding, aerating, seeding and watering. This turf will be less susceptible to pests and diseases and more resilient in the face of weather events such as drought and extreme heat and cold.
“New grass varieties are coming onto the market that are better adapted to our changing environment,” said Dr. Michael Brownbridge, Vineland’s research director, horticultural production systems. “New perennial ryegrass and tall fescue cultivars exhibit different growth habits from traditional fescues and ryegrasses, and are similar to the popular Kentucky bluegrass, offering a more aesthetically-pleasing appearance. Newer varieties also have superior root systems, allowing them to access water and nutrients more efficiently from the soil.”
In addition, some new cultivars harbour naturally occurring endophytic fungi that produce alkaloids conferring higher levels of resistance against pests, including two of the most prevalent: hairy chinch bug and European chafer (commonly known as white grubs).
“Several of these new grass varieties have performed well in research trials evaluating resistance to pests,” Brownbridge said. “The high alkaloid ryegrass, Natural Knit perennial ryegrass, Natural Knit tall fescue and insect-resistant mixes incorporating high alkaloid ryegrass, were found to be the most resistant against chinch bugs while European chafer grubs avoided feeding on the insect-resistant mixes.”
Using the correct grass variety is only the first step in maintaining a healthy lawn. Since pesticide bans took effect in many residential areas across the country, biocontrol agents are more frequently used. For instance, nematodes are the standard for grub control in turf. The Vineland team found that when applied in late August/early September, two nematodes, Heterorhabditis bacteriophora and Steinernema glaseri, consistently provided about 50 per cent control of European chafer. Later applications or those made in the spring were relatively ineffective. A new nematode, Steinernema scarabaei, is even more effective. Although challenging to produce, it is a robust nematode that survives in the soil for several months and can potentially provide extended control of white grubs.
The nematode Steinernema carpocapsae, rosemary oil and a sprayable formulation of the fungus Metarhizium anisopliae are also effective against chinch bugs when used in July.
Lawns and gardens can be healthy without the use of pesticides. It is important to use a combination of approaches – the right type of grass and proper lawn care practices with the use of effective biocontrol agents, as needed – to achieve best results.
This research was supported by the Ontario Turfgrass Research Foundation, the Quebec-Ontario Cooperation for Agri-Food Research, Agricultural Adaptation Council, the Cosmetic Use Pesticides Research and Innovation (CUPRI) program, Landscape Ontario and the Canadian Ornamental Horticulture Research and Innovation Cluster (COHA).