Adams County
CO Noxious Weeds

Home > CO Noxious Weeds > Leafy Spurge

Leafy Spurge

Management

Cultural ManagementLeafy Spurge

Seeding and Maintaining selective perennial grasses can be an effective tool. Early emerging grasses that utilize early season moisture have reduced spurge density and limited the spread and establishment of new infestations. Sequential glyphosate (e.g. Roundup) applications followed by a seeding of Luna pubescent wheatgrass, Ephraim crested wheatgrass, intermediate wheatgrass, Sherman big bluegrass, or Bozoisky Russian wild rye, has shown to be effective in reducing an infestation of spurge in Wyoming. Proper grazing management and eradication of small spurge infestations are always desirable cultural tools.

More complete information on grasses can be found on the Grass Seeding on the Eastern Front-Range of Colorado page or by contacting the Natural Resources Conservation Service.

Mechanical Management

Mechanical control of spurge is difficult because it is a creeping perennial. However, multiple stresses applied to plants are very effective. Frequent mowings through summer reduces the herbicide application rate needed in the fall. Mowing spurge a regular intervals 4 to 6 times per spring/summer is an effective stress treatment that will reduce root food reserves and prevent seed set. Mow as plants regrow and before flowering stage. Spurge's milky sap has been known to gum up mowers.

Cultivation can be done at two to four week intervals, but is costly and can bare soil to erosive factors. Research results are not available that indicate whether stand reduction or eradication can occur from the sole use of mechanical treatments.

Biological Management

Sheep grazing leafy spurgeBoth sheep and goats have been found to be effective grazers of spurge. (The milky sap of this weed is incurious to cattle and horse mouths.) Grazing sheep can commence after spring regrowth reaches two to six inches tall, but before the flowering bract stage. Goats can graze spurge at any time. Grazing can proceed to mid August or so. Do not overgraze. If animals are turned into a site after the spurge has set seed, quarantine animals in a corral for seven days before releasing them into a non-infested pasture. Sheep may need a breaking in period of two weeks before they readily eat spurge.

Flea BeetlesSeveral insect species have been released by the USDA/APHIS that affect spurge. Of the flea beetles three species have been found to be most effective. Apthona nigriscutis, Apthona lacertosa, & Apthona flava have been found to be effective after three years on large infestations. Contact the Adams County Weed Department or your local extension office for details on these flea beetles.

Herbicide Management

Herbicides that have been effective when used independently or in some combinations are: picloram (Tordon), dicamba (Banvel), 2,4-D (aquatic formulations) Glyphosate, imidazol and fosamine are suitable for use on riparian sites. Picloram and dicamba can injure or kill trees. If a solo herbicide treatment is used, application time is critical. Refer to the table below for more information.

 

Herbicide
Labeled site*
Rate (per acre)
Application time
Remarks

Tordon 22K

R&P, NC

1.0qt.-repeat annually 3-4 years.

2.0qt.-Treat 2 consecutive years.

Spring following appearance of true flowers and/or fall regrowth.

Use the 2qt. rate as a spot treatment. Upper rates may cause grass damage.

Tordon 22K

+ 2,4-D Amine

R&P, NC

1pt. + 1qt.

Spring following appearance of true flowers and/or fall regrowth.

1 Treatment per year for 2-4 years should provide good leafy spurge control.

Banvel

+ 2,4-D Amine

R&P, NC

1qt. + 1qt.

Spring following appearance of true flowers and/or fall regrowth.

Two treatments per year for 1-4 years should provide good leafy spurge control.

2,4-DAmine

All

1qt.

Early Spring

Prevents seed formation. Retreatment may be necessary to prevent seed formation.

Plateau

NC, Riparian

12.oz

Fall treatment prior to hard freeze.

Can safely be used under trees and riparian areas. Add methylated seed oil surfactant.

* R & P = Range and Pasture; NC = noncrop; Crop = cropland; F = fallow; All = all of these sites.

Read the label to insure the herbicide is labeled for your application site.

 


 

Disclaimer | EEO | Ask an Expert | Webmaster - Last updated 9-3-08

Extension Home | CSU Home

CSU Extension Home