Latest articles





This quick-spreading weed gets an early start

Noxious weeds: Canada thistle

Spring brings lovely native flowers, but also noxious weeds. The aggressive perennial Canada thistle is a favourite of disturbed soils of all types. It starts sending shoots from horizontal roots to the surface of soil around mid-April, with flowers to follow in mid-June and continuing throughout the summer. Easy to distinguish from other weeds, this […] Read more


Don’t be fooled by this weed’s pretty flower

Noxious weeds: Field scabious

Field scabious was introduced as an ornamental from Europe and is now taking over roadsides and pastures. It can be found throughout central Alberta and has the ability to invade even undisturbed plant communities, such as hayfields. Once established it is very difficult to control. Flowers can be a purple- to blue-coloured clustered head, resembling […] Read more



You won’t raise a glass to this invasive weed

Noxious Weeds: Absinthe wormwood

A tough, semi-woody perennial plant native to Europe and Asia, absinthe wormwood typically grows in stems and forms in a clumping habit. The most distinguishing feature of the plant is its finely divided leaves combined with a silvery-grey colour. Absinthe wormwood also has a very strong and distinct odour which is very similar to sage. […] Read more


This tree is also a noxious weed

Common buckthorn, otherwise known as European buckthorn, has been found in two locations in Alberta — in Edmonton along the North Saskatchewan River and in Stettler County. It was originally brought to North America from Eurasia as an ornamental, but soon spread throughout the continent. High seed production and excellent tolerance to Canada’s climate allow […] Read more



Noxious weed found throughout Alberta

Noxious Weeds: Wooly Burdock

Woolly burdock is found throughout Alberta and will grow in most soil types. It prefers moist, loamy, and well-drained soils which are in direct sunlight. This noxious weed is commonly found on disturbed sites, but has also been found growing in gardens for herbal use. Woolly burdock can only reproduce by seed, but is self-fertile […] Read more




This toxic hitchhiker is a threat to livestock

Noxious Weeds: Hound's tongue

Hound’s tongue is a weak competitor and doesn’t do well in healthy rangeland — but it compensates for that by being an excellent hitchhiker. This noxious weed produces up to 4,000 seeds per plant, and each one is barbed and easily attaches itself to clothing or fur. It also produces toxic alkaloids that cause irreversible […] Read more


A wolf in sheep’s clothing

Noxious Weeds: Baby's breath

Many people think of baby’s breath as a cute, delicate filler flower found in rose bouquets. The real plant found in the Prairies couldn’t be further from this image. This weed has a taproot that can reach the astonishing depth of four metres, and it can grow as wide as 41 centimetres in circumference. And […] Read more