Longspine sandbur

Identification & Biology
Alias' : burgrass, field sandbur
Latin Name : Cenchrus longispinus
Category : Terrestrial Plants
Description :
  • Annual grass
  • Stems (0.25-0.75 m) typically grow upright, but can branch and spread flat along the ground
  • Leaf sheaths are flattened, very loose, and have a tuft of short hairs where they join the blade
  • Leaves are light green
  • Seeds are round and spiky (4-6 mm wide)

 

Longspine sandbur reproduces entirely from seed. Germination begins in early spring and continues throughout the summer. Seeds begin to develop near the beginning of July. The spiky burs readily hook on to human clothing and animal fur.

Habitat

In British Columbia, sandbur occurs only in the Okanagan Valley, as far north as Penticton, and there are very limited outbreaks in the lower Similkameen Valley (Keremeos). It prefers sandy or well-drained soils and readily invades disturbed ground. Sandbur typically infests vacant lots, gravel parking areas, roadsides and unpaved trails. More recently, this invader has moved onto agricultural lands, particularly where crops border roads, in sandy headlands, between crop rows and in other locations where there is limited vegetation to compete with the sandbur.

Impact & Risks

Spines on the seeds readily attach to footwear, clothing, animals, tires, machinery and supplies. The spines can injure the feet, hides, mouths, eyes and digestive tracts of livestock, and can also injure people. They are especially problematic to fruit pickers working in orchards and vineyards. This ‘hitchhiking’ is the primary mechanism for dispersal of sandbur.

Prevention & Mitigation
  • Monitor your property regularly during the growing season to watch for sandbur
  • Reduce the amount of bare ground/ minimize soil disturbances • Re-seed or plant disturbed soils
  • Develop clear protocols for cleaning vehicles, machinery and footwear, such as check points or cleaning stations Placement of bins, equipment and supplies is also an essential part of reducing the spread of sandbur. Seeds can easily attach and be unknowingly transported from one location to another. Clearly mark locations for parking vehicles and machinery. Areas heavily infested with invasive plants should be considered “out of bounds” until measures are taken to remove or otherwise destroy the plants. Long-term control of sandbur can be achieved by reducing the amount of seeds in the soil. Remove plants before they produce seeds and continue this practice for several years.
Treatment & Disposal

Hand removal or hoeing is effective for controlling small outbreaks. Shallow tilling (~2.5 cm deep) of young plants can be effective in larger areas. Deeper tilling is not recommended since this practice may bury seeds which will continue to germinate for several years afterwards. Mowing is not an effective method of control. Chemical control is also an option. Before applying herbicides, read the label for full use and precautionary instructions. Consult the most recent edition of the Alberta Agriculture and Forestry Crop Production Guide for the selection and application of chemicals to protect your crop.

Okanagan Distribution

Priority Level Definitions

Watch For - Poses a significant threat (very high risk) and does NOT presently occur in the region OR is relatively new to the region and is very limited in extent.
High - High risk/impact; limited population with significant potential to spread in the region.
Medium - Medium risk/impact; limited distribution – broader population distribution with potential to spread further in a region.
Low - Low risk/impact; may be widespread or not, may be of concern in specific situations with certain high values – e.g. specific agriculture crops. Some species may be treated primarily with biological control agents.