Category Archives: Pesticides/Fertilizers

Surviving a Municipal Cosmetic Pesticide Ban: Using low-risk herbicides

Nematodes are being applied to control European Chafer on a home lawn. Photo courtesy Deborah Henderson


By Deborah Henderson, PhD

There are three basic modes of action for low-risk herbicides:
● killing or ‘burning’ down top growth with no effects on roots;
● inhibition of seed germination; and
● attack with a plant pathogen (i.e. biological control), killing all parts of the weed.

The first two modes of action are familiar to those using chemical herbicides, but the third is new. Biological controls for weeds are pathogens that live by feeding on the weed. They tend to be very specific for certain types of plants and require specific environmental conditions. Though a bit fussy about their conditions, these controls can work extremely well.

Read the full article: Surviving a Municipal Cosmetic Pesticide Ban

Surviving a Municipal Cosmetic Pesticide Ban: Pesticide risks

By Deborah Henderson, PhD

Since 2003, there has been a big increase in availability of low-risk or ‘soft’ products in the market, fuelled largely by cosmetic pesticide bans. It should be emphasized ‘soft’ and ‘low-risk’ do not imply ‘no risk.’ One should not be fooled into thinking these products have no toxicity for your family or pets. They are environmentally protective, and less toxic than those they replace, but they should be treated like the chemicals they are. They need to be kept out of reach of children and pets, users should wear protective gear if the label directs, and any ‘re-entry’ interval instructions must be observed.

Most new products for use in municipalities with bans are on B.C.’s “excluded pesticide” list (the fifth and lowest risk category).

Read the full article: Surviving a Municipal Cosmetic Pesticide Ban

Surviving a Municipal Cosmetic Pesticide Ban

By Deborah Henderson, PhD

Managing pests, diseases, and weeds within cosmetic pesticide bans can be a challenge. Every municipality has different rules and even provincial bans regulate in dramatically different ways across the country. While most people understand and agree with the concern about overuse of pesticides and protecting the environment and their health, the turf industry is also faced with maintaining rather high standards for the cosmetic value of landscapes and a very real gap between what is expected and what is possible. It is difficult to be the bearer of bad news.

Whether provincial or municipal, the recurring themes of Canadian legislation is to ban:
● active ingredients;
● products based on their use patterns; or
● products based on concentration or package size.

Read the full article: Surviving a Municipal Cosmetic Pesticide Ban

The Increasing Need for Organic Matter: Soil water conservation

Mature trees with a large area of pine bark mulch surrounding them. Photo courtesy Gro-Bark

By Chelsea Stroud, B.Sc. Agr. (Hort.), GRP

A combination of organic materials benefits any type of soil. Increasing certain kinds of organic material in soil will help retain moisture and ensure adequate drainage. For annual/perennial-type garden beds, a blend of composted pine bark, compost, and humus peat at a ratio of 80:20 organic to mineral soil is excellent.

For locations where trees will be used, incorporating more mineral soil provides additional structural support. Using 30 to 50 per cent mineral soil with a blend of 50 to 70 per cent coarse and fine organic materials provides the structure required for trees and excellent moisture retention. Turf areas should not be ignored; you should use fine blends of compost and CPM, and incorporate them before seeding or through a topdressing program at a rate of 6 to 12 mm per season.

Mulching around established trees helps conserve water. Often, plants do not survive under large-canopy trees, resulting in thin turf and exposed soil. Using a layer of mulch helps prolong the tree’s life.

Read the full article: The Increasing Need for Organic Matter

Managing Pesticide-free Home Lawns: Future considerations

The percentage of turfgrass and weed coverage of three separate renovation studies (two spring and one fall). LS means were calculated using ANCOVA. Treatments with different letters are shown to be different at the P<0.05. Image courtesy Kathleen Dodson[/caption] By Kathleen Dodson, MSc.

The presented research displays the importance of understanding weed encroachment in home lawn environments. Consideration of what seeds will be germinating from the soil seedbank during certain times of the year plays an important role when it comes to timing cultural practices.

While spring renovations encourage annual weed growth, these weeds cannot thrive in a home environment and therefore die out as the season progresses. Fall renovations promoted greater establishment of persistent turf weeds in the sward, suggesting in pesticide-free environments, home lawn renovations in the spring may provide a better-quality lawn long-term.

Using cultivation practices to promote turf health is important in the home lawn environment; however, timing and weather conditions play an important role on the effectiveness of certain cultivation practices. For example, spring power-raking can play an important role in weed control, but the cultivation must be timed so the environmental conditions are favourable for cool-season turfgrass growth. Why power-raking works is the dicot weeds cannot tolerate the tearing action as well as turfgrass plants that have evolved to perform well under moderate disturbances. By setting back the weeds, the turf can recuperate and become the dominant plant in the stand. However, if the environmental conditions are not favourable for turfgrass growth, the recuperative ability of the turf will be drastically diminished.

Managing pesticide-free home lawns in Canada requires an understanding of the growth habits of cool season grasses so maintenance practices can be timed to maximize their effectiveness for the promotion of turfgrass growth over weed growth. While the traditional spray approach to home lawn maintenance for weed control is now limited under the cosmetic pesticide ban, it is still viable to maintain a healthy, usable lawn by employing well-timed cultural practices.

Read the full article: Managing Pesticide-free Home Lawns