||Short lived, creeping
||Early Spring (few
the first year)
toadflax is a native of southeastern Europe's Mediterranean region.
It was cultivated as an ornamental in Europe for nearly four centuries
and was brought to the western coast of North America for that purpose
plant can produce up to 500,000 seeds from late June until early
October. Seeds usually develop first in the lower flowers while
the upper flowers may still be budding. Although seeds may lay dormant
in the soil for over 10 years, usually only 50% of them will germinate.
Germination can occur in the Fall, but most develop in early Spring,
usually on south-facing slopes first. As toadflax develops it becomes
very competitive for available water, but while young it is vulnerable
to dehydration and competition by other plants.
toadflax plants form prostrate rosettes,
, spending most of their energy establishing an extensive root system.
Roots can grow 4-10 feet deep, and develop buds along their surface,
capable of producing new shoots. This allows dalmatian toadflax
plants to produce new shoots before native plants do, limiting the
resource availability, and ultimately crowding out other plants
toadflax plants live an average of 3-5 years. Populations can disappear,
"die out," and then return again a few years later from dormant
seeds or living roots.
toadflax will displace existing plant species
and their associated animal life. Where grasses have been replaced
there is a increase in surface runoff, erosion, and sediment yields
in streams. Loss of forage can impact big game and domestic livestock
carrying capacity, especially on winter range. The plant can be
mildly toxic to cattle that eat it, but this is rare.
plant has been used lightly as browse for deer and the seeds are
used by some birds and rodents. Unlike wildlife, sheep will eat
this as a major food source. On harsh, sparsely vegetated sites,
toadflax can actually help stabilize the soil.
plant usually invades disturbed open sites, especially areas that
are grazed moderately to intensely (primarily by sheep). Dalmatian
toadflax prefers well-drained coarse-textured soils, and becomes
highly competitive in dry areas, particularly southern and southeastern
facing slopes. Plants can be found along roadsides, in vacant lots,
cemeteries, gravel pits, open fields, and rangeland. Once established,
the condition of the existing native plants will have little impact
in slowing the expansion of this plant.
requires the use of several tools. Each population may require different
treatments due to high genetic variability. Some of the most effective
controls known are:
• Hand pulling for six years. This depletes the root reserves on
small patches, preventing further vegetative growth. The site must
be revisited and maintained for the next 10-15 years.
• Reseeding with a mix of competitive native plants. This can reduce
seedling establishment, but will only slow established populations.
• Grazing should be deffered until late in the season. This allows
desired native plants time to compete. Sheep are effective in suppressing
stands and reducing seed production during flowering.
• Over six different parasitic
insects species are currently being used with variable impacts.
• Herbicide success is variable, with chemical type and concentration
often site-specific (example herbicides: Telar and Tordon 22K [look
at herbicide label: free search]).