Glossy or alder buckthorn (Rhamnus frangula)



Description:

Appearance: Tall understory shrub or small tree, grows up to 20' high, has a spreading loosely branched crown, often multiple stems at the base. Brown bark with elongate silvery corky projections (Caution: native plums or cherries have a similar bark).

Branches: Cut branch exposes yellow sapwood and orange heartwood.

Leaves: Alternate, think, and ovate or elliptic smooth, dark glossy, margins are not toothed; stay green late into fall.

Flowers: Inconspicuous, appear in May or June, clustered in the axils of leaves.

Fruit: Ripens progressively from a distinctive red to a dark purple in August and September. Seeds are viable for 2 - 3 years in the soil.

Roots: Extensive fibrous root system.

Ecological Threat:

  • Aggressively invades wetlands including acidic bogs, calcareous fens and sedge meadows. Also grows in upland habitats, tolerates full sun to deep shade.
  • Plants leaf out early and retain leaves late into the fall creating dense shade.
  • Seeds have laxative effect on birds who disperse them.
  • Introduced to North America as ornamental shrub, often planted in hedgerows.
  • Glossy or alder buckthorn is on the MDA Restricted noxious weeds list in Minnesota.

Control Methods:

Mechanical
Prescribed fire for seedlings

Pulling in small infestations (weed wrench)

Chemical
Cut-stump treatment with glyphosate; cut-stump or basal bark spray treatment around the stem with triclopyr

DNR permit to work in public water may be required



Minnesota Conservation Volunteer magazine article The Trouble With Backyard Buckthorn