Skip to main content

Siberian peashrub

(Caragana arborescens)

Photo of Siberian peashrub
Photo credit: Elizabeth J. Czarapata

Shrub or multi-stemmed tree in the pea family, with individual yellow flowers.

Overview

Other names for this plant include:
  • Common names: Siberian peatree, pea tree
  • Scientific names: Caragana arborescens var. pendula; Caragana fruticosa; Caragana arborscens var. redowskii; Caragana sibirica; Robinia altagana var. fruticosa; Robinia caragana
Ecological threat:
  • Invades coniferous and hardwood forests, plantations, forest edges, savannas, trails, right-of-ways.
  • Reported as invasive throughout much of the Upper Midwest and Great Plain states.
  • Extremely adaptable to a variety of soil conditions, salt and cold temperatures.
  • It contains nitrogen-fixing microbial symbionts, altering natural soil chemistry and associated plant communities.
  • Inhibits growth and establishment (allelopathic) to some grasses.
  • Produces a chemical that reduces herbivore predation and pathogen establishment.
Overview map of Siberian peashrub classification in WI
Restricted (orange) counties

Classification in Wisconsin: Restricted (cultivars Lorbergii, Pendula, and Walkerii are exempt)

Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for Siberian peashrub was based upon this literature review [PDF] developed by the department.

Identification

Leaves & stems: Shrub or multi-stemmed tree. Alternate, pinnately compound leaves with 8-12 leaflets. Young leaflets are silky in texture, while mature leaflets are hairless. Tips of leaflets contain a spine.

Flowers: Yellow, singular flowers characteristic of the pea-family. Flowers are fragrant and borne on long stalks.

Fruits & seeds: Seeds borne in 1-2 inch pods, smooth and brown with sharply pointed tips. Pods eject seeds when mature.

Roots: Nitrogen-fixing symbionts form nodules on the roots.

Control

Mechanical:
  • Dig up individual plants. For larger populations, mow as close to the ground as possible. Continual mowing is needed as plants rapidly re-sprout.
  • Cover the infestation with black landscape fabric/plastic in early spring, when leaves emerge. Keep covered for a minimum of one growing season.
  • Consecutive prescribed burns may be a successful control option, with sufficient fuel loads and fire-appropriate habitats.
Chemical:
  • Cut-stump treatment with glyphosate.
  • Cut-stump or basal bark treatments in fall with triclopyr.

Photos

View Siberian peashrub pictures in our photo gallery!

Resources

Sources for content:
  • Shortt, Katelyn B., Vamosi, Steven M. 2012. A review of the biology of the weedy Siberian peashrub, Caragana arborescens, with an emphasis on its potential effects in North America. Botanical Studies, 53:1-8.
  • Minnesota Department of Natural Resources
  • National Park Service
Links for more information: