Noxious weeds in Gilpin County
Photo credit: Irene Shonle
Leafy spurge(Euphorbia esula)
Quick Facts
Reproduces from vigorous root stalks and numerous seeds.
Roots may grow more than 15 feet deep.
When capsules containing the seeds dry they explode and distribute
seeds 1-13 feet from the plant.
Seeds may remain viable in the soil for over 8 years. In Gilpin
County, it will go to seed by mid-late July.
It can reduce cattle carrying capacity of rangeland or pastures
by 50 to 75 percent.
Leafy spurge is difficult to control. Its extensive root system
has vast nutrient stores that let it recover from control attempts.
Long-term persistence is imperative.
Roundup (glyphosate) is most effective when applied sequentially
(1.0 quart per acre (A) at one month intervals, coupled with fall
grass seeding. Make the first application at the beginning of June
and a second application one month later. Occasionally, leafy spurge
will recover from these Roundup treatments.
Sheep or goats can be used to help control leafy spurge. Research
from Montana State University indicates sheep may consume up to
50 percent of their diet as leafy spurge with no harmful signs.
Introduce sheep to leafy spurge in early spring when the weed is
succulent. Goats will consume leafy spurge at almost any time during
the growing season.
Biocontrol releases so far in Gilpin have not been effective.
 Leafy
spurge produces a milky sap, which can cause eye injury.
This plant can be confused with yellow toadflax in the vegetative
stage. To determine which weed you have, carefully break a leaf
in half and look for a bead of milky sap coming out of the midvein.
If there is milky sap, it is leafy spurge.
Other Links For Further Information:
http://www.ext.colostate.edu/pubs/natres/03107.html
http://www.colostate.edu/Depts/CoopExt/Adams/weed/spurge_id.htm
http://www.colostate.edu/Depts/CoopExt/Adams/weed/spurge_mgt.htm
http://www.mtweed.org/Identification/spurge/spurge.html
http://www.team.ars.usda.gov
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