GFM Network News


Perennial sow-thistle.

Perennial sow thistle costs farmers across Alberta

Noxious Weeds: Perennial sow thistle causes yield loss and acts as a host for pests

Often found in high densities across Alberta, perennial sow thistle seems to be a noxious weed that doesn’t quit. Not only does this pest cause significant yield loss in many crops, but it’s a host for several plant pests that attack economically important crops such as alfalfa, winter wheat and canola — just to name […] Read more

Devil’s trumpet — also known as jimsonweed, hell’s bells, loco-weed, and devil’s cucumber — is easily identified by either sight or smell.

Devil’s trumpet is a potentially deadly invader

Noxious Weeds: Jimsonweed

Although its exact origin is unknown, devil’s trumpet — otherwise known as jimsonweed — is found in many countries around the world in both agricultural and ornamental settings. Introduced to this province as a contaminant of agricultural seed, this smelly weed is under review by the provincial Agriculture Ministry and it has been recommended to […] Read more


Yellow clematis gets its name from its lemon-yellow nodding flowers.

Another invader from the buttercup family

Cultivation is not successful and no chemicals are registered for control

Yellow clematis, a perennial vine related to the buttercup family, can become quite invasive if proper precautions are not taken. In Alberta, it has been designated as noxious for this reason. Often purchased, however, from gardening stores as a bedding plant, this weed can spread by wind which can take the seeds far beyond the […] Read more



Seed from Canada thistle can germinate eight to 10 days after flowering, but roots — not seeds — are the main way that this noxious weed spreads.

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

The flower of field scabious is pretty but the weed can invade hayfields and other grassy areas and be widely dispersed via baled forage.

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


The barbs on the seed heads of Woolly Burdock allow them to easily attach to fur or clothing.

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

Hound’s tongue isn’t palatable to grazers, but when consumed in hay, it is poisonous, especially for cattle and horses.

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


The size of this baby’s breath plant shows how well it can prosper in the Alberta landscape.

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