Strategy: Also known as Catchweed (not Catchweed bedstraw) this is a nasty little European invader which produces a small blue to violet flower that will form pointed and somewhat flat seed heads with 4 barbed nutlets (very similar to Houndstongue). These barbs allow this plant to hitch-hike onto anything and almost everything (like socks). This plant is somewhat viney, but generally only grows among itself forming dense thick pockets. Once the weed dies in early summer it turns into a mass of rust to brown tangled vines. It can be found along roadways, ditch banks, and disturbed sites.
Attack: This tough invader does a great job of attaching its way onto any kind of host. Once there it germinates and chokes out all sunlight robbing the other plants of its nutrients and water. The seeds cling onto all things, thus spread far and near to all sites, thus can be found anywhere. This plant is not desirable as a feed. The plant can make harvesting some crops difficult as the ‘vines’ can wrap around harvesting equipment and clog them up or over heat the bearings.
Defense: As this is an annual plant mechanic control is possible. Hand pulling is easy in the early spring, but once the plant matures it becomes quite brittle and will break off and re-grow in a short amount of time. Disking larger patches will work as long as you can keep the ‘vines’ from wrapping around disks and cutting heads. Herbicides such as 2,4-D and Banvel are effective when applied early in the spring. Products such as Telar XP or Opensight can stretch the treatment season. As this has short tough hairs in the leaves and stems make sure you use a good surfactant to get the herbicide into the plant.
The Defense – As this is an biennial plant, mechanical control can be quite effective. If you decide to ‘dig it’ out with a shovel just make sure that you get at least three inches of the root. We are having a difficult time trying to find an insect that is allowed in the country as this plant is in the borage family, and we have a few native borages that the insect like. Many herbicides are available that work well.
PLEASE NOTE –The proper use and application of herbicides can be an effective way to control and eradicate noxious and invasive plants. Before using herbicides, always carefully follow the label and safety instructions on the label. While we recommend the use of herbicides as one of the effective tools for integrated pest management, the Idaho Weed Awareness Campaign assumes no liability for herbicide applications.
Opensight at 2.5 ounce/acre to rosettes. As plant bolts, increase the rate to 3.0 to 3.3 ounce/acre up to early bud stage. Add 1 quart of 2,4-D/acre after the bud stage. Click to view label.
Telar® XP and Escort® XP are two that work extremely well. One positive about this treatment is that they will not be very harmful to range species such as Sagebrush and Buckbrush and you can spray in the spring summer or fall.