Rural Roots Special Edition - Weeds of Distinction | Page 4

OXEYE DAISY CANADA THISTLE
Noxious Noxious
Leucanthemum Vulgare, Chrysanthemum Leucanthemum
Oxeye Daisy is a perennial that spreads primarily
by seed, but also has rhizomes. It occupies
a variety of habitats and grows exceptionally well
in nutrient poor soils. Oxeye Daisy has a white
daisy-like flower growing on a smooth, frequently
grooved and sometimes branched stem. The
leaves progressively decrease in size upwards
on the stem. Basal and lower leaves are
lance-shaped with ‘toothed’ margins and are
alternately arranged.
Look alike: Scentless Chamomile.
Mechanical: Horses, sheep and goats will readily
graze Oxeye Daisy. Cattle however, avoid Oxeye
Daisy but when used in a high stock density
and short grazing periods can encourage cattle
to graze and trample the plant. Trampling can
also bring dormant seeds to the surface and
under normal conditions; those seedlings will
dry-out and perish before becoming established.
Repeated mowing prevents the spread of seed,
but can promote re-sprouting of stems. Hand
picking is most effective when the rhizome roots
have been removed. Due to the nature of Oxeye
Daisy’s shallow root system, intensive cultivation
will control an infestation.
Herbicides such as Aminopyralid alone or in
a product mix are registered for use.
mdlsr.ca/Agricultural-Publications
Cirsium Arvense
Canada Thistle is an aggressive perennial that can
spread by creeping roots and by seed. Canada
Thistle can grow in a variety of soils but thrives
in disturbed areas and overgrazed pasture/
rangelands. Its flower heads are urn-shaped,
vary in colour being purple, pink or white and
the bracts are spineless. The leaves are lance-
shaped, dark green in colour, grow alternately on
the stem and the edges can vary from smooth
with no spines to irregularly lobed with sharp
spines. Canada Thistle is the only thistle, native or
introduced, with separate male and female plants.
Mechanical: Control of the root system is the
only effective method. A combination of cutting
and herbicide application during active growth
periods (early spring and late fall) is best. Sheep
and goats will readily graze rosettes before plants
reach the spiny stage. Note; invasive plant species
should not be considered as forage, unless
no other control method can be utilized. Mowing
and hand picking will gradually deplete the
energy reserves in the root systems.
Herbicides such as 2, 4-D, Aminopyralid,
Chlorsulfuron, Clopyralid, Dicamba, Glyphosate
Hexazinonem Metsulfuron-methyl, MCPA and
Picloram are registered for use.