[APWG] QUESTION: is anyone out there working on garden loosestrife (Lysimachia vulgaris) control?

[Messick, Katie]

In King County, Washington, we have an extremely large and aggressive
population of garden loosestrife (Lysimachia vulgaris).  Our plants are
often fasciated, can grow to over 8 feet tall, and outcompete many other
aggressive emergent plants such as purple loosestrife (Lythrum
salicaria), common cattail (Typha latifolia) and spirea (Spiraea
douglasii) to create large monocultures.  It also grows in deep shade
and is slowly replacing the understory beneath long established willow
wetlands.  

 

We have had some control success using triclopyr (Renovate3), but
although it knocks back the tall plants, it doesn't kill them
completely.  Manual control has not proven effective due to long brittle
rhizomes.  

 

I'm beginning to think we have a mutant population in our county since I
can't seem to find anyone else who is concerned about it.  If any of you
have any experience with garden loosestrife, I would dearly love to
know!

 

Thanks,

Katie

 

Katie Sauter Messick

Aquatic Weed Specialist

King County Department of Natural Resources and Parks

201 South Jackson Street, Suite 600

Seattle WA 98104

(206) 296-0290

www.kingcounty.gov/weeds
<file:///C:\Documents%20and%20Settings\MessickK\Application%20Data\Micro
soft\Signatures\www.kingcounty.gov\weeds>  

 

 

 

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