<div dir="ltr"><div>Lori,</div><div> </div><div>We have a pretty bad problem with Oriental lady's thumb (Polygonum cespitosum, Persicaria longiseta) here at Shenandoah National Park. Like the native PA smartweed, it has pink flowers/fruit, but they're smaller, and the leaf sheath around the stem (ocrea) is fringed with long hairs. It's our second most widespread and abundant nonnative weed, and is often found in near monocultures. Oriental lady's thumb seems to really thrive and persist in mesic, higher elevation sites in the park. At lower elevations it seems a bit more ephemeral. </div><div> </div><div>Assuming your smartweed is confirmed as this or another of the small handful of nonnative species, you're correct--you won't find much guidance on dealing with it. We've found it's easy to kill, but not very easy to kill without collateral damage. A glyphosate product such as Rodeo (54% glyphosate) can be used at low concentrations (0.5% has been pretty consistently effective, 0.25% less so) on heavy infestations. Weed whacking it close to the ground before seed set can knock it back. In upland areas, preemergent products (e.g. pendimethalin, prodiamine) can be useful, and are probably your best option for avoiding damage to native perennials. But these may not be an option if you're near a stream. Contact herbicides such as pelargonic acid (e.g. Scythe at 5 to 10% concentration) are also pretty effective, if applied early and before rigid stems develop. Flaming with a propane torch should work too, if you're into that.</div><div> </div><div>Since mowing probably leaves enough above-ground tissue for the plants to rebound, I doubt it would effectively control Oriental lady's thumb. And certainly if it's being mowed after seed set, the seeds are being thrown far and wide. </div><div> </div><div>Hope this is somewhat helpful, should you need to deal with this plant.</div><div> </div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Jul 13, 2015 at 6:13 PM, Lori Bowes <span dir="ltr"><<a href="mailto:lrbowes2@yahoo.com" target="_blank">lrbowes2@yahoo.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div style="color:rgb(0,0,0);font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:10px;background-color:rgb(255,255,255)"><div><span>Hi. I get confused about smartweed/knotweed but I can say that every time I have asked a plant-knowledgeable person about our smartweed, they felt it was the invasive type.</span></div><div><span></span><br></div><div dir="ltr"><span>I think in my haste to get this posted before a Grounds meeting I relied on a google entry that told me that PA smartweed was invasive so I thought that was the one we have.</span></div><div dir="ltr"><span></span><br></div><div dir="ltr"><span>I guess I need to affirm that my ocrea is not bristled.</span></div><div dir="ltr"><span></span><br></div><div dir="ltr"><span>Assuming ours is the invasive species, if you have guidance on whether mowing is worsening the problem, please let me know.</span></div><div dir="ltr"><span></span><br></div><div dir="ltr"><span>Thanks,</span></div><div dir="ltr"><span>Lori</span></div><div><div class="h5"> <br><div><br><br></div><div style="display:block"> <div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:10px"> <div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:16px"> <div dir="ltr"> <font size="2" face="Arial"> On Monday, July 13, 2015 4:40 PM, Art Gover <<a href="mailto:aeg2@psu.edu" target="_blank">aeg2@psu.edu</a>> wrote:<br> </font> </div> <br><br> <div>I like PA smartweed. It’s native and charming and fills space. Sure about the ID?<br><br>Be well.<br><br>Art<br><br>Penn State Wildland Weed Management<br>116 ASI Building<br>University Park, PA 16802<br><br>(814) 863-9904<br>(814) 863-7043 FAX<br><a href="http://plantscience.psu.edu/wildland" target="_blank">http://plantscience.psu.edu/wildland</a><br><br>> On Jul 13, 2015, at 16:37, frazmo <<a href="mailto:frazmo@gmail.com" target="_blank">frazmo@gmail.com</a>> wrote:<br>> <br>> Any thoughts out there in MAIPC land? If possible, copy the asker, <a href="mailto:lrbowes2@yahoo.com" target="_blank">lrbowes2@yahoo.com</a>, directly also as I'm not sure she's on our list. Cheers, Steve Young<br>> <br>> ---------- Forwarded message ----------<br>> From: "<a href="mailto:lrbowes2@yahoo.com" target="_blank">lrbowes2@yahoo.com</a> [NativePlantseast]" <<a href="mailto:NativePlantseast@yahoogroups.com" target="_blank">NativePlantseast@yahoogroups.com</a>><br>> Date: Jul 13, 2015 12:34 PM<br>> Subject: [NativePlantseast] Smartweed management?<br>> To: <<a href="mailto:NativePlantseast@yahoogroups.com" target="_blank">NativePlantseast@yahoogroups.com</a>><br>> Cc: <br>> <br>> <br>> <br>> <br>> <br>> My community has an abundance of Polygonum pensylvanicum on a turf hillside that abuts a stream (on the other side of which is a wooded area) and a terraced native plant area (with asters, goldenrods, grasses, viburnums, violets, etc). The Polygonum is thriving amongst the turf and is constantly invading the native plant terrace.<br>> <br>> <br>> <br>> We have some flexibility in how we manage the turf hillside in terms of mowing. Can anyone offer some thoughts or guidance?<br>> <br>> <br>> <br>> I haven't found much on the web in the way of guidance for this topic.<br>> <br>> <br>> <br>> Thanks,<br>> <br>> Lori<br>> <br>> Arlington, VA<br>> <br>> <br>> __._,_.___<br>> Posted by: <a href="mailto:lrbowes2@yahoo.com" target="_blank">lrbowes2@yahoo.com</a><br>> Reply via web post • Reply to sender • Reply to group • Start a New Topic • Messages in this topic (1) <br>> yahoogroups website(to subscribe/unsubscribe/ read archived posts, change options): <a href="http://undefined/group/NativePlantseast?soc_src=mail&soc_trk=ma" target="_blank">http://www.yahoogroups.com/group/NativePlantseast </a><br>> <br>> You may also unsubscribe by sending an email to:<br>> <a href="mailto:NativePlantseast-unsubscribe@egroups.com" target="_blank">NativePlantseast-unsubscribe@egroups.com</a><br>> Post message: <a href="mailto:NativePlantseast@egroups.com" target="_blank">NativePlantseast@egroups.com</a> <br>> Subscribe: <br>> <a href="mailto:NativePlantseast-subscribe@egroups.com" target="_blank">NativePlantseast-subscribe@egroups.com</a> <br>> <br>> <br>> VISIT YOUR GROUP<br>> • Privacy • Unsubscribe • Terms of Use <br>> .<br>> <br>> <br>> __,_._,___<br>> _______________________________________________<br>> MAIPC mailing list<br>> <a href="mailto:MAIPC@lists.maipc.org" target="_blank">MAIPC@lists.maipc.org</a><br>> <a href="http://lists.maipc.org/listinfo.cgi/maipc-maipc.org" target="_blank">http://lists.maipc.org/listinfo.cgi/maipc-maipc.org</a><br><br><br></div> </div> </div> </div></div></div></div></div><br>_______________________________________________<br>
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<br></blockquote></div><br><br clear="all"><br>-- <br><div class="gmail_signature">Jake Hughes<br>Lead Biological Science Technician<br>Shenandoah National Park<br>3655 US Hwy 211 E<br>Luray, VA 22835<br><a href="mailto:Jake_Hughes@nps.gov" target="_blank">Jake_Hughes@nps.gov</a><br>Office: 540-999-3500 ext 3492 <br>Fax: 540-999-3697<br></div>
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