Characteristics

• Biennial
• Separate male and female plants
• White flowers open in full sun and close in evening
• Hairy stems
• Similar to Bladder Campion and Night Flowering Catch Fly

How it Grows

• Emerges early in the spring
• Taproot forms first followed by spreading lateral roots
• New plants can start from root pieces
• Grows in reduced tillage, forage crops, roadsides, waste areas
• Female plants capable of producing 24,000 seeds

Prevention 

• Know the source when purchasing hay and straw
• Request a weed seed analysis certificate when purchasing forage seed
• Prevent the plant setting seed by removing it through hand-picking

Characteristics

• Plants can be summer annuals, winter annuals, or short-lived perennials
• Has daisy-like flowers with raised yellow centers and white petals
• Hairless stem has light green leaves that alternate around it
• Leaves are very finely divided and smooth

How it Grows

• May reach about 1 meter tall
• Will flower in late June through to September
• Will produce around 300,000 to 500,000 seeds per plant
• Seeds will survive in soil for long periods of time (up to 20 years)

Prevention

• Tarping loads of grain and bales
• Mowing non-cropped areas about twice a year
  Hand pull, hoe, and till in small areas before it flowers
• Harvest and till weedy areas separately, which helps keep weeds in confined area
  Shallow tillage on hot, dry days
• Plant competitive crops such as barley or winter wheat

Characteristics

• Perennial
• Leaves are silvery-grey, alternate, lancolate, and undivided, sage-sage-like odor when crushed
• Flowers are yellowish-green borne on a spike-like panicle
• Fruit is numerous small, round seed.

How it Grows

• Gradual deep tap root
• Inhabits waste areas and pastures
• Out competes forage plants

Prevention

• Mechanical Control (tillage)
• Chemical control through spot treatments

Characteristics

• Bright white and yellow flowers and resembles snapdragon flowers
• Hairless stems are fully covered in numerous, hairless leaves
• Bushy appearance is due to the new clumps of shoots along the side of the creeping roots

How it Grows

• Will flower from June through to the fall
• One stem produces up to 5,000 seeds
• Seeds from Toadflax will germinate as soon as they spread and may remain in the soil for up to 3 years

Prevention

• Constant cultivation will control it but will not prevent it
• Mowing helps control but will not eliminate weed
• Seed at a heavier rate than normal to prevent competition
• Biological control with special species of beetle and weevil feed in the flower and prevent seed production
• Chemical control through treatments with Grazon

Characteristics

• Deep-rooted perennial
• Can spread through re-vegetative re-growth of the roots
• Small, yellowish green flowers found in clusters are enclosed in yellow-green brackets
• Plant contains a milked white latex, which is toxic to some animals and can cause blistering and irritation on skin

How it Grows

• Can grow to a height of 3 feet in the spring
• Can be found growing almost anywhere, especially in sandy and marginal soils
• Seeds occur in clusters of three; seed capsules will explode when dry

Prevention

• Goats and sheep will readily graze this plant
• Intensive cultivation throughout the growing season, or fall-only cultivation can reduce the presence
• Mowing has proven somewhat effective mechanical methods against this plant
• There are a few herbicides that have had success reducing the density of infestations when used at proper timing
• Five types of flea-beetles and two types of moths are available for bio-control

Characteristics

• Very distinguishable by its strong fragrance, when leaflets are crushed
• Bright yellow flowers are arranged in clusters and are flat-topped
• Leaves resemble the leaves of a rose

How it Grows

• Flower clusters can be as numerous as 200
• Stems of tansy have been known to grow to 6 feet tall
• Seeds are the primary source of reproduction, it can also spread through root stalks

Prevention

• Tansy does not endure tillage
• Mowing (dead heading) the flowers while they are still yellow will also help to control seed production
• High seeding rates
• Herbicide options are available through Flagstaff County

Characteristics

• Most recognized characteristic of any thistle is the spiny, prickly leaves
• Flower head is shaped like a vase
• Bracts are spineless and appear purple, pink, or white in colour
• Each flower has an odour, which attracts honeybees

How it Grows

• Flowering occurs between mid-June and into September
• Plants can reach heights of 1.2 to 1.5 meters tall
• Extensive root system where vertical roots will grow downward to 7 meters in order to reach the water table
• Plants can be produced from small pieces of root and shoots
• Each of the flower heads could contain about 90 seeds, which means a plan could produce close to 5,200 seeds
• Seeds can remain in the moist, loamy soils for up to 21 years

Prevention

• Regular cultivation
• Pulling or hand-cutting several times through the season
• Late spring burns in May and June
• Chemical control can also be used; 2-4D, products containing clopyralid or glyphosate are useful