A nodding thistle before it blooms getting a visit from nodding thistle gall flies.  |  Mike Raine photo

Weed of the Week: nodding thistle

Unlike some of its cousins, such as Canada thistle, nodding thistle nearly always begins from a seed, which grows to the height of a person — one with an agreeable personality because once it gets its purple hairdo, it starts nodding. Each one of those big purple flowers can contain up to 250 seeds, and […] Read more

Wild buckwheat is an annual pest that is best controlled in spring when it is small.  |  Mike Raine photo

Weed of the Week: wild buckwheat

Wild buckwheat climbs the ladder of crop pest importance as the season passes. Alberta farmers say in polling it is their least favourite weed. It can be tough to kill, degrades grain and oilseed samples, messes up harvests and will trip up the odd field scout. The ropy pest can prompt grain buyers to refuse […] Read more

Kochia's hairy leaf surface has the ability to resist chemical application, requiring more careful nozzle selection and higher water volumes than many post-emergent weeds in the crop.  |  Mike Raine photo

Weed of the Week: kochia

Kochia, despite being identified as one of the most dangerous weeds in the West, remains a growing problem in the region. Droughty conditions have allowed this tough competitor to flourish, even if it is only a few plants making it to maturity at the field corners or on the fence lines, where it often ends […] Read more


This salty dog might look pretty, but it’s no friend of farming.  | Getty Images

Weed of the Week: saltcedar

My great aunt farmed for her whole career. She used to say, “a sharp hoe is as good as a rain any day.” And there are weeds where no registered chemistry is available, or that can be applied in riparian areas so removal is one of the only options. Saltcedar is one of those, and […] Read more

Redroot pigweed is an annual pest on prairie farms. The seeds of redroot pigweed can remain viable for up to five years.  |  Michael Raine photo

Weed of the week: redroot pigweed

As the weather warms up, redroot pigweed can become a serious problem for some crops that aren’t strong competitors. Worse yet, amaranthus retroflexus, a dicot weed in the Amaranthaceae family, is developing resistance, or appears to at least have become harder to control with Group 2 chemistries. In Ontario it has become resistant to Group […] Read more


Cleavers are considered to be sixth for weed abundance in canola and seventh for all annual crops in Western Canada according to Agriculture Canada.  |  File photo

Weed of the Week: cleavers

Cleavers have become a constant in the northern grain belt of Western Canada and pose significant threats to canola yield and quality. The pest’s ability to operate as either a winter annual, getting up early in the spring as toughened, established competitor or as a spring-germinated weed. First, the good news. If the fall is […] Read more

Foxtail barley tolerates the saline conditions that occur once it dries out after periods of excess moisture. It has managed to establish itself on a significant number of acres in Western Canada recently. | File photo

Weed of the Week: foxtail barley

Some weeds have flourished with the increase in no-till acres over the past 20 years. One of them is foxtail barley, known to biologists as hordeum jubatum. It has become an increasing concern after our series of wetter years and with the expansion of saline-affected soils. Foxtail barley tolerates the saline conditions that occur once […] Read more

Weed of the Week: cleavers

Last week I addressed a weed that I called the scourge of the south. For more northern grain belt farmers, this week I will discuss the scourge of the north, more commonly known as cleavers. Just as we saw a significant increase in the acres infested with kochia, we have seen cleavers spread across agricultural […] Read more


Kochia contains saponins, alkaloids, oxalates and nitrates that can be toxic to livestock, so it must be controlled in their diet.  |  File photo

Weed of the Week: kochia

I would like to discuss two weeds over the next couple of weeks. One I will refer to as the scourge of the south and the other as the scourge of the north. Unluckily, I have worked in an area where the two come together so have experience with both. The scourge of the south […] Read more

This annoying weed goes by many names —  lady's purse, witches pouches, rattle pouch, clapper's pouch — all derived from the appearance of the seed pods, which resemble small purses. | File photo

Weed of the Week: shepherd’s purse

Reducing tillage has increased cash flow, boosted bottom lines and improved soil health. One of the downsides has been minor weeds becoming major problems. Some fall annual weeds have thrived where steel now fails to find them. Worse, pests like shepherd’s purse have managed to escape some of the handiest herbicides, such as Group 2 […] Read more