Perennial Pepperweed
Perennial Pepperweed
Perennial Pepperweed Rosette

Brassicaceae or Mustard Family
Lepidium latifolium

Other Common Names:
Broad-leaved peppergrass or tall whitetop.
Growth Habit: Perennial, grows typically 1 to 3 feet tall but can reach 6 feet.
Leaves: Bright-green to gray-green leaves have a whitish midvein and are pointed at the tip. Leaves do not clasp the stem. Basal leaves are covered with a waxy layer.
Stems: Stem leaves are smaller than basal leaves and are alternately arranged on the stem.
Flowers: Less than 1/8 inch wide and consist of four white petals arranged in a cross and are borne in dense, rounded clusters at the terminal part of branches.
Roots: Creeping root system can penetrate depths of up to 10 feet.
Seeds: Fruit is flat, rounded, slightly hairy reddish-brown capsule that contains two tiny seeds. Infestations can produce over 6.4 billion seeds per acre, seed viability is short.
Reproduction:Reproduces by roots and seed.
Habitat: Most frequently found in riparian areas, marshes, irrigation channels, wetlands, and floodplains.

Handpulling: Handpulling can be an effective method of control for small infestations if large portions of the root system are removed with the stems. Roots should be bagged and removed from the site to be dried and burned.
Mowing: Mowing should be carried out at the first sign of flowering at a height of approximately 4 inches. Herbicide treatments may be necessary for re-sprouting. Care should be taken to only mow in areas where desirable plants can withstand repeated mowing.
Biological Control: N/A
Grazing: Grazing is only recommended for infestations that have not yet established thick monocultures and have other forage plants growing within the infestation. Seeds remain viable after passing through the systems of livestock, so care should be taken when moving animals to non-infested areas. They should be contained for five days and fed weed-seed free hay before they are moved.
Herbicides: There are a number of herbicides that can be used to control infestations of perennial pepperweed on a yearly basis, though repeated applications will be needed to decrease the size of infestations and/or eradicate it. The following herbicides are labelled to control perennial pepperweed. Always consult product labels and read them carefully to ensure correct species/land management usage and chemical application.

Trade Name:  Active Ingredient:   Rate:   Efficacy:   Comments:  
 Escort metsulfuron  .75-1 oz/acre  most effective if used when plant is in rosette to bud stages with a non-ionic surfactant Cannot be used near wells, surface water or shallow ground water
Telar  chlorsulfuron  1 oz/acre  most effective if used when plant is in rosette to bud stages with a non-ionic surfactant  
Plateau  imazapic   10 oz/acre most effective if used at flower stage with a methylated seed oil surfactant 
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