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Minnesota DNR- The Truth About Exotic Species:European(Common) Buckthorn Page 1 of 2 <br /> ��; � �� � ,� _;� <br /> t��� �,�� �� �ti ,,, � <br /> ;�* ; ' °�� �,� �;. <br /> ��..� ' �Y „�` Y,-r <br /> ��� <br /> �=rp �h'tna�esOtQ D��b � � ��. � �;; <br /> � � .- � <br /> 1 ' � _ •� � � �. <br /> _ : �:": �.�� ��.����-����'� <br /> Rl:amnus cathartica <br /> ��� ,m„�9M"` <br /> �����u � �_a_ Description: <br /> � "'� Shrub or small tree reaching height of 25' (7.6m); <br /> ;. ` ''' trunk diameter up to 10" (25cm); crown spreading <br /> and irregulaz; bark gray to brown, rough textured <br /> ` • when mature and often confused with Prunus sp. <br /> Inner bark yellow. Twigs often tipped with a <br /> �� spine. Small black fruits up to 1/4" (0.6cm) <br /> diameter containing 3-4 seeds. Leaves broadly <br /> elliptic, rounded to pointed at the tip, and toothed. <br /> Upper and lower leaf surfaces smooth. Upper leaf <br /> surface dark glossy green. Leaves stay green late <br /> � into fall, after all other leaves have fallen. <br /> �;,' <br /> ��::: <br /> �, Concern: <br /> R. cathartica was introduced to North America as <br /> an ornamental shrub. It is native to Eurasia. The <br /> fruit causes a severe laxative effect, quickly <br /> distributing the seeds through birds. Common <br /> buckthorn invades mainly woodlands and <br /> savannas, although it may also be found in <br /> prairies an open ields. Once estab is e uckthorn crowds or shades out native shrubs and <br /> herbs, often completely obliterating them. European buckthorn control is also of interest to <br /> small grain producers: the shrub is an alternate host of the crown rust of oats. MN <br /> Interagency Exotic Species Task Force 1991 future threat ranking of SEVERE, current threat <br /> SEVERE. <br /> Controls: <br /> Late March to Earl�• May: Prescribed fire is one method proposed for controlling <br /> buckthorn in natural areas. In the upper Midwest conduct burns as soon as leaf litter is dry; <br /> resprouts will be less ��igorous due to low carbohydrate levels. Burning every year or every <br /> other year in established stands may be required for 5-6 years or more. Unfortunately <br /> buckthorn seedings often grow in low litter areas, unsuitable for prescribed fire more often <br /> than once every 3-4 ��ears. In dense stands seedlings and saplings may be cut and dropped on <br /> site, creating fuel for future fires. Buckthorn seedlings appeaz to be very vulnerable to fire, <br /> perhaps due to their poorly established root structure. Fire will top kill a mature plant, but <br /> resprouting does occur. Uprooting of smaller seedlings with a weed wrench is another non- <br /> chemical control. <br /> May to October: Excellent results are reported using lpart Garlon 3A(44.4%triclopyr) in 1 <br /> part water with dye on cut stumps. MN DNR Region V State Parks found a 1:4 dilution of <br /> the above also effecti�-e. Product label suggests avoiding the spring sap flow. Gazlon 3A <br /> undiluted applied to cut stumps between first budding in May, through summer, to hard <br /> freeze in fall was 95% effective in preventing resprouting (Boudreau and Willson). Hennepin <br /> Co. MN parks report 1:1 Garlon 3A:water with antifreeze solution controls buckthorn during <br /> winter application. <br /> http://www.dnr.state.mn.us,'tish_and_wildlife/exotics/buck.html 5/14/O 1 <br />