All information provided by the Alberta Invasive Species Council. For more on the various noxious and prohibited noxious weeds, please visit the The AISC website.

Oxeye Daisy, Canada

oxeye daisy

The Oxeye Daisy stands out prominently in the landscape, as there are no native white flowered daisies in Alberta. Often perceived to be a ‘pretty’ wildflower, is actually an aggressive invader. It is a perennial that spreads primarily by seed, but also by shallow, creeping roots. The greatest impact of this plant is on forage production in pastures and meadows. Cattle avoid oxeye daisy and so any pasture infested decreases forage available for grazing. Horses, sheep and goats, however, will readily graze oxeye daisy and can be used in companion grazing situations to control oxeye daisy. Dense stands of oxeye daisy can decrease plant diversity and increase the amount of bare soil in an area.

Control: Mowing before bloom can reduce seed set but will not control the plant. Mowing during or after flowering will disperse seeds. Because of its shallow root system, oxeye daisy can be controlled with cultivation.

Creeping Thistle, Canada

thistle2

These spiky fellows show up every year across most of Alberta, and are aggressive and creeping. They have purple or white flowers, grow up to 120 cm tall, and are ridged and slightly hairy.

Control: Chemical application in the late fall is the most effective way of dealing with this little pest.