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

[Terressentials]

Crazy idea, but have you tried using 100 grain vinegar?  It's super
effective -- 100% kill -- on many noxious plants including Canadian
Thistle.  It's not as effective for those plants that spread via roots,
though it will kill foliage and flowers on such creepers.

Diana




----- Original message -----
From: "Messick, Katie" <Katie.Messick at kingcounty.gov>
To: apwg at lists.plantconservation.org
Date: Fri, 31 Jul 2009 16:09:59 -0700
Subject: [APWG] QUESTION: is anyone out there working on garden
loosestrife     (Lysimachia vulgaris) control?

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\Messick-
K\Application%20Data\Micro  soft\Signatures\www.kingcounty.gov\weeds>