Also Known As
Cleavers, Stickywilly, Cleaverwort, White Hedge, Bedstraw, Goosegrass, Gripgrass, Scarthgrass, Velcro Plant
Catchweed bedstraw, Galium aparine L., native to North America and Eurasia, is an annual broadleaf plant with a shallow, branching taproot. The stems of catchweed bedstraw are square in cross-section, weak, mostly unbranched, and grow to about 6 feet long, but are unable to stand on their own, so they often clamber over upright plant species.
Left on its own, catchweed bedstraw remains low and sprawling, forming dense, tangled mats. Hairlike bristles cover the stems and leaves of the plant; these bristly hairs are responsible for its characteristic tangled growth habit and the “sticky” way it clings to clothing and animals.
The leaves of catchweed bedstraw are linear, narrow, and mostly whorled, with 6–8 leaves per whorl. Inconspicuously small, pale green to white flowers occur on long stalks in the axils of upper leaves. Two-lobed, spherical fruits separate into 2 nutlets, ranging in shape from nearly round to kidney shaped at maturity and covered with sticky hooked hairs that aid in dispersal.
Individual plants typically produce 100–400 seeds, which require burial to germinate and remain viable in the soil for a couple of years. While this species spreads only by seeds, a related species (northern bedstraw, Galium boreale) is a perennial with a spreading root system.
Catchweed bedstraw prefers shady, moist sites, but tolerates full sun with sufficient moisture. Commonly found in waste sites, roadsides, and other disturbed areas, catchweed bedstraw can grow in a variety of habitats, including along fence lines and in forests and woodlands, meadows, prairies, abandoned fields and cultivated crops.
Bedstraw is a troublesome agricultural weed, considered a major weed of crops such as cereals, hay, and oilseed crops. Not only does it become tangled with the crop or equipment at harvest, but its seeds are extremely difficult to remove from harvested grain, vegetable seeds, and oilseeds. Heavy infestations of catchweed bedstraw can cause significant yield losses. Catchweed bedstraw can host several nematode, insect, and disease pests; on the other hand, its flowers provide a food source for some beneficial insects. If ingested by animals, bedstraw forage can imflame the digestive tract or act as a diuretic. Entanglement in sheep wood reduces value.
Historically used as an herbal remedy for various ailments, its dried and roasted fruits have also been used to make a coffee substitute (in fact, the plant is in the same family as coffee, Coffea spp).
Cultural: In agricultural areas, growth of catchweed bedstraw can be suppressed by planting a competitive crop or ground cover, although preliminary consideration should be preventing it by eliminating contaminated crop seed, machinery, livestock, and manure. Long-term control of catchweed bedstraw relies on removing existing plants before they flower and produce viable seed.
Mechanical: For small infestations, hoeing or hand-pulling can be effective, especially when soil is damp; care must be used, however, because the weak stems of bedstraw break easily making it difficult to remove the roots. Regular mowing at a low height may be an option, although cutting of the plant to 2–3 inches has been reported to actually increase biomass production up to 30% compared to uncut plants. Winter annual bedstraw should be controlled in the fall after germination with tillage or an herbicide.
Chemical: Control of bedstraw is different depending on the crop it infests. Herbicide options are available in cereal crops, field peas, and herbicide tolerant canola varieties. There are no herbicides registered for control of cleavers in conventional canola. Herbicides that can be effective for the control of bedstraw (dependent upon crop) are fluroxypyr, sulfosulfuron, carfentrazone, imazamethabenz, diuron, dicamba, oxyfluorfen and glyphosate.
Biological: No insects or other biological agents are available to control catchweed bedstraw. While livestock will eat the plant, it is not a nutritious food source since it produces so little biomass; moreover, germination percentages actually increase following passage of the seed through animal digestive tracts so grazing should not be allowed after seed production.