Cypress Spurge

Scientific name: Euphorbia cyparissias

Identification and Impacts

Cypress spurge (Euphorbia cyparissias) is a low growing perennial that overwinters as root and crown tissue. Cypress spurge reproduces by seed and lateral root buds. Leaves are linear, approximately 1/2 to 1 1/4 inches long and 1 to 2 mm wide. Upper stem leaves that occur near the inflorescence are yellow or yellowish-green in color. Leaves are stalkless, alternate, narrow and linear to lance-shaped. Stems are 4 to 32 inches high, hairless, green to yellowish green in color and branch in the upper portions. The leaves and stems emit a milky, toxic sap when broken. Flowers are yellowish-green usually turning reddish green towards maturity and are clustered in bunches at the ends of stems.

The plants milky sap is an irritant and may cause dermatitis or rashes. Although sheep may eat it, the plant is toxic to horses and cattle. Animals should not be pastured where spurges grow. Humans should be careful and avoid contacting the plant with bare skin as it can cause skin irritation for some people.

Cypress spurge is an invasive ornamental plant that is native to Eurasia. It prefers direct sunlight, but is tolerant to the shade. It commonly occurs in dry to moderately moist meadows, pastures, forest edges, roadsides, Rights-of-Way, cemeteries, and gardens. Cypress spurge is popular in xeriscaping and rock gardens and generally does not occur on intensively cultivated soils. The soil seed reserve is estimated to be at least eight years.

The key to effective control of cypress spurge is preventing the establishment of viable plant communities. When establishment has occurred, there are different control methods to consider. Like most perennial plants, exhausting the nutrient reserves in the root system is important in controlling cypress spurge. Using a combination of mechanical and herbicide treatments in combination can achieve eradication over time.

Cypress spurge is designated as a “List A” species in the Colorado Noxious Weed Act. It is required to be eradicated wherever found in the State. For more information visit www.colorado.gov/ag/weeds and click on the Noxious Weed Management Program link. Or call the Douglas County Weed Management at 303-660-7480.

Integrated Weed Management Recommendations

Cultural – Keeping desirable vegetation healthy and thick will help keep invaders out. Prevent the establishment of new infestations by minimizing disturbance and seed dispersal. Survey your land regularly to detect new invaders and eradicate any new populations quickly.

Biological – Biocontrol agents are not included in the prescribed management plans by the State for List A Species. Eradication is the management objective of all List A’s. No biocontrol agent for Cypress spurge is available. For more information on biocontrol in Colorado, please contact the Palisade Insectary of the Colorado Department of Agriculture at 970.464.7916.

Mechanical - Hand pulling or digging is a viable option when managing new, small cypress spurge infestations. Tillage may simply encourage its spread. Be sure soil is moist and extract the entire root system. When handling plants wear rubber gloves and eye protection to protect yourself from the irritating milky sap.

HERBICIDES

NOTE: The following are recommendations for herbicides that can be applied to range and pasturelands unless otherwise noted. Not all products listed are for use near homes. Please read label for exact rates. Always read, understand, and follow the label directions. The herbicide label is the LAW!

HERBICIDE

RATE

APPLICATION TIMING

Quinclorac (Paramount – non-crop – general use) 16 oz product/A + 2 pt/A methylated seed oil or crop oil concentrate Apply at the flowering stage. (Spring time)
2,4-D + dicamba (Rangestar – general use) 2 qt. 2,4-D (2.0 lb/ai) + 1 qt dicamba/A (1 lb ai) Apply at the flowering stage. (Spring time)
Picloram (Tordon 22K-restricted use) 2-4 pints product/acre + 0.25% v/v non-ionic Apply in spring at full bloom, or in the fall during regrowth.

Additional Resources

Online Services:

Weed Management

Public Works Operations Division

3030 North Industrial Way
P.O. Box 1390
Castle Rock, CO 80109
Phone: 303.660.7480
Fax: 303.814.3319
noxweeds@douglas.co.us

Office Hours

8:00 a.m. - 5:00 p.m.