| Walla
Walla County Noxious Weed Control Board
Weed
of the Month
Mediterranean
Sage (Salvia aethiopis L.)
Mediterranean sage,
also known as African sage, is a biennial or short-lived perennial
plant with a stout taproot and square stems, reaching up to 3 feet
tall. The leaves are fleshy and aromatic when crushed.
Mediterranean sage seeds
require moisture to germinate, so germination can occur in the spring
or the fall. The first year of growth, the plant develops a rosette
of large grayish woolly leaves. Multibranched stems are produced
the second year with gray to blue-green, woolly, felt-like leaves.
Large lower leaves are stalked and lobed with coarsely-toothed blades
up to one foot in length. Upper leaves are smaller and clasp the
stem. Leaves of mature plants shed some hair and become wrinkled,
showing prominent venation.
Flowers are white to
yellowish, about ½ inch long, and borne in clusters on many
branched stems from June to August. The smooth brown seeds are about
1/8 inch long, with dark veins. One plant may produce up to 100,000
seeds which spread easily when the mature plant becomes a tumbleweed.
Mediterranean sage is spread even longer distances by livestock,
wildlife (including birds), roadside vehicles, contaminated gravel,
and as a contaminant in hay.
Meadow sage (S. pratensis
L.) resembles Mediterranean sage, but usually has blue flowers
and is more coarsely hairy. Common mullein (Verbascum thapsus)
rosettes may be confused with Mediterranean sage rosettes. Mullein
leaves are yellowish-green, not stalked, the margins are entire,
and when the mullein leaves are crushed, they do not smell like
sage.
Mediterranean sage is
native to Europe and was introduced to the United States as a garden
ornamental and possibly as a contaminant in alfalfa seed. Mediterranean
sage was identified as early as 1892 in California but in Washington,
this species was first identified in 1951 in Columbia County, with
about 400 acres found along the Touchet River.
Mediterranean sage will
initially inhabit disturbed areas, but it can spread to non-disturbed
land. The plant is typically found in degraded rangeland communities,
disturbed sites, fields, rangelands, roadsides and some agronomic
crops. It is not palatable to livestock.
Prevent establishment
by management of rangelands to prevent overgrazing. In small infestations,
individual plants can be dug out, severing the tap root 2-3 inches
below the crown. Tillage can be effective. Mowing several times
during the growing season will prevent seed production but rosettes
are not affected.
Herbicides can be effective
when applied with a surfactant to help penetrate the woolly leaves.
Picloram kills existing plants and seedlings with a spring application
with a residual effect on new seedlings. Clopyralid will kill existing
plants without residual effects. BE SURE TO FOLLOW ALL PESTICIDE
LABEL INSTRUCTIONS AND PRECAUTIONS.
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