Management Guide for Lonicera maackii (Amur honeysuckle) Species Lonicera maackii (LOMA6)1,2 Common Name Amur honeysuckle Name Common name2, 3, 4 - Amur bush honeysuckle, bush Family: Caprifoliaceae Synonyms: honeysuckle, late honeysuckle. Form: Woody vine/shrub Former species name4- Xylosteum maackii Ruprecht Habitat:3, 4 Roadsides, railroads, woodland borders, some forests, fields, abandoned or disturbed lands and yard edges Occurrence:1, 2, 4 Native range:2, 3, 4, Ranges from NE United States and Ontario, to Eastern Asia (Japan, Korea and Manchuria, and China) North Dakota and east Texas, as well as Oregon Flowering time2, 3 - May – early June Weed class: OR- N/A, WA- N/A, BC- N/A Weed ID: 2, 3, 4 Can grow up to 16’ (5 m) in height, opposite ovate to lance-ovate leaves 3.5-8.5 cm long with acuminate tips, dark green above and lighter underside with pubescent veins. White (aging to yellow) bilabiate tubular flowers in erect pairs of 1.5-2 cm long and 3-4 cm wide at throat, on peduncles shorter than the petioles, fragrant. Fruit are bright to dark red spherical and 6 mm in diameter, ripening in late fall. Bark is gray to tan and exfoliates partly in vertical strips. Look-a-likes: see photos below Other Lonicera:4 - L. morrowii, L. quinuelocularis & L. tatarica (non-natives) Weed distinction4, 9, 14 Amur honeysuckle blooms later than other honeysuckles and has short pedicils with nearly sessile flowers and berries. Distinguishable from most native Lonicera by its bright red fruit and hairy styles, as well as leafing out and keeping leaves later than native Lonicera. L. morrowii has hairier leaves & white flowers. 14 *Twigs being hollow is reported by many to be a trait of native and non-native honeysuckles alike with no consensus, but possibly Lonicera non-native to North America are hollow, as is L. maackii. 9, 10, 11, 12, 13, 15, 16 Ecological Impact:2, 3, 4, 18 Can form large stands preventing native shrubs and understory, and one of first plants to leaf out in spring, shading out natives. Persistent berries area spread by birds but birds nesting in the honeysuckle suffer higher predation. It is considered to have a high probability of spreading wherever it has established and is allelopathic where non-native.17 It has been shown to reduce water in ephemeral wetland, harming amphibians and other ephemeral wetland obligate species. Most severe impact is on forest edges & ephemeral wetlands

Management Guide for Lonicera maackii

Control Methods

Large Scale: Chemical  Glyphosate is very effective for non-sensitive habitats with Amur honeysuckle at 1% concentration for foliar spray or as 50% for cut-stump & basal bark application.8, 9 Timing9 o Spray in late fall after natives have senesced or any time except spring. o Cut stump & basal bark treatments should be from fall to early winter before active growth.

 Triclopyr has been effective for controlling Amur honeysuckle at TNC preserves in Hawaii but should be used where surface and sub-surface runoff will be minimum8. The cut-stump, drill & fill (drill 3/8” bit holes at downward slant into the crown, 1 per 1” of trunk diameter) or basal bark9) methods of application may be more effective than foliar spray for taller honeysuckles and where desirable plants are near the honeysuckle.6 Basal treatment may protect native recovery from herbivores.6 Timing9 o Spray from summer to fall. o Treat via cut-stump, drill & fill, and basal bark in fall when sap will move from the stem to the root.

 Pentra-Bark- apply to bark to open up the lenticels then apply Glyphosate to bark.5

Prescribed burning4, 8, 9, 19 - burns can remove the above-ground growth and kills seedlings, but resprouting may occur from the buds on the crown below soil surface, so follow treatment may be needed.

Mowing/ cutting20– large patches can be mowed/cut and the resprouts are either foliar sprayed with herbicide or recut. 4 Repeated cutting in the same year is necessary to prevent increased fruiting as a response to cutting. Can also try bagging crowns cut 3’ high to solarize-kill resprouts if you cannot return to plants soon enough after cutting.5 Timing19 o Cut honeysuckle plants in the spring and summer, or cut in spring and spray resprout in the late spring/early summer (tested using glyphosate on similar invasive L. morrowii).7 o Cutting Amur honeysuckle in fall may lead to resprouts freezing back in winter, but regrow in spring. Small Scale:  Cut and burn on the stump5 - will kill the stumps and remove the debris from cutting.  Digging out5, 18, 20 – smaller plants can be dug out by hand, taking care to remove the crown of the plant.  Pulling with weed wrench5, 8- bush honeysuckles are reportedly removable via weed wrench if not too big for the wrench clamp/”jaws”. Last Updated By: Lauren Clark Date/Time: 9/24/2019

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Management Guide for Lonicera maackii

References: 1. https://plants.usda.gov/core/profile?symbol=LOMA6 2. https://www.invasiveplantatlas.org/subject.html?sub=3040 3. http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=d617 4. https://www.cabi.org/isc/datasheet/31192 5. https://docplayer.net/41193751-Twenty-five-ways-to-remove-amur-honeysuckle-lonicera-maackii.html 6. Cipollini, Kendra., Ames, Elizabeth, & Cipollini, Don. Amur Honeysuckle (Lonicera maackii) Management Method Impacts Restoration of Understory Plants in the Presence of White-Tailed Deer (Odocoileus virginiana). Invasive Plant Science and Management. 2(1):45-54. (2009). http://www.bioone.org/doi/abs/10.1614/ipsm-08-108. 1.short 7. Love, J. P., and Anderson, J. T. “Seasonal effects of four control methods on the invasive Morrow’s honeysuckle (Lonicera morrowii) and initial responses of understory plants in a Southwestern Pennsylvania old field.” Restoration Ecology. 17-4 549-559. (2009). https://www.cabi.org/isc/abstract/20093231008 8. https://www.invasive.org/gist/products/handbook/methods-handbook.pdf 9. Evans, Chris. “Bush Honeysuckle: Identification, Control, & Potential Spread.” Illinois Wildlife Action Plan. Invasive Species Campaign Cooridinator. (2014). https://www.se-eppc.org/alabama/2014/830_BushHoneysuckleALIPC.pdf 10. https://www.habitatmatters.org/honeysuckle.html 11. https://calscape.org/Lonicera-ciliosa-(Orange-Honeysuckle) 12. https://www.nrcs.usda.gov/wps/portal/nrcs/detail/ct/technical/ecoscience/invasive/?cid=nrcs142p2_011130 13. https://www.oardc.ohio-state.edu/weedguide/single_weed.php?id=54 14. https://www.illinoiswildflowers.info/trees/plants/morrow_hs.htm 15. http://dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=911 16. http://dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=683 17. Romanek, Daniel M., Competition and Allelopathic Effects of Native and Invasive Populations of Lonicera Maackii: A Comparative Analysis. (2009). Browse all Theses and Dissertations. 806. https://corescholar.libraries.wright.edu/etd_all/806 18. https://theoec.org/blog/amur-honeysuckle-lonicera-maackii/ 19. http://stophoneysuckle.org/location/ 20. https://www.fs.fed.us/database/feis/plants/shrub/lonspp/all.html

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Management Guide for Lonicera maackii

Photos:

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Management Guide for Lonicera maackii

Look-a-like Photos:

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