I removed a Silver Lace from a garden but left some roots. I know it is a Polygonum species, is it like Japanese knotweed?
Silver Lace vine (Polygonum aubertii) it is indeed related to Japanese knotweed (Polygonum cuspidatum) and as such, have a tendency to be invasive.
This vigorous vine quickly covers fences and other structures with fragrant white blooms that last through the summer and into the fall. Its versatility allows it to succeed in full sun or shade, under any pH or soil type. It spreads by underground rhizomes that can easily re-sprout if left behind. Mechanical methods of elimination will work but it will probably take few seasons before you can completly declare victory.
Please refer to the following document from the Washington Weed Control Board for more information: www.co.whatcom.wa.us/publicworks/weeds/pdf/SilverLaceVine2.pdf
Best of luck.