How Long will residual herbicides prevent weeds for?

Residual herbicides offer around 9-12 months of weed control

Are Herbicides Safe?

 Herbicides are chemical compounds designed to react with plant chemistry but many do react with human chemistry and their level of safety to animals and humans varies depending on the product.

Chemical products should always be treated with extra care and are generally dangerous if mishandled. Many herbicides require the use of personal protective equipment to load and spray and have listed re-entry periods (how long you have to wait to re-enter the area safely). All herbicides in Canada have registered labels with important use information regarding mixing, storing, disposal and applying the product which can be found online. Refer to the Material Safety Data Sheet for more detailed information on reactivity and chemical information.

How long do herbicides take to work?

This depends on the herbicide, but generally herbicides take two to four weeks to show their full effect on the plant. This is dependent upon the type of herbicide used, temperature, plant species and ground moisture levels.

When is the right time to spray weeds?

This varies depending upon the weed. Some weeds are better controlled before they can bloom in the spring, whereas with residual herbicides the timing is less important. In general it is good to spray weeds before they have a chance to produce seeds, but in some cases plants can produce seeds that lay dormant for decades. in that case timing for spraying those weeds is less of a factor in treatment success.