Mullein
 Family Scrophulariaceae
Verbascum thapsus
Designation/Status
Arizona Noxious Weed List -
Not Listed
Federal Noxious Weed List – Not Listed
Origins
Europe and Asia
Plant
Characteristics
Life Cycle: Biennial or perennial, in
the first year it produces a low rosette up to 60cm in diameter,
in the succeeding year is grows a flowering stem. Fruit is an
ovoid, numerous six sided seeds, may produce 100,000-180,000 seeds
per plant. Seeds may remain viable for over 100 years. Flowering
begins in late June of the second year and ends in early August.
Plants rarely live for a third year.
Visual Appearance: Basal leaves are
oblong, flower stem is densely woolly with branched hairs. The
corolla has five yellow petals.
Habitat
Found in neglected meadows and pasture lands,
along fence rows and roadsides, in industrial areas. Prefers areas
with a mean annual precipitations is 50-150cm.
Control Measures
Mechanical and Cultural:
Scarification and mowing must be done continually for control. It
is important to minimize the availability of bare soil by sowing
quickly growing native plant species. Manual removal of plants
before flowering, cutting off the tops or stirring the surface
soil to dry out seeds, removal of rootstocks has been effective as
well. Burning is best followed by either repeated burning or by
re-vegetation with native species.
Biological: Mullein is easily out competed in areas
with densely vegetated ground cover.
Chemical: The epidermal hairs on the leaves can protect
the plant form aqueous solutions, best control with the use of
Tebuthiuron, repeated applications at half the initial rate will
suppress growth, a pre-emergent can also reduce the viable seed
bank
Other Points of Interest
Introduced as a medicinal
herb, in the mid-1700s to Virginia. It has also been used as a
fish poison, and often grown as an ornamental.
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