Knots on Lots

Japanese Knotweed, Polygonum cuspidatum, was introduced in the United States from Asia as a decorative plant, but soon grew out of control. Because knotweed loves moist environments and can grow in poor soil quality, it can be found all over the Pittsburgh’s region riverbanks and has spread to roadsides, lawns, and, of course, vacant lots. (Most of the 27,000 empty lots in Pittsburgh have Knotweed growing on them.) Currently there is no great way to deal with the Knotweed, besides removing the root system completely. Since the roots can grow up to 3 feet deep and 23 feet horizontally, removal is extremely difficult. If left unattended, this plant will continue to outcompete native plant species.


So what do you do when you have acres upon acres of this stubborn, unruly plant growing all over the City that is just making urban gardeners, landscapers and communities frustrated and not providing any real productive use?

You know what they say, when life hands you knotweed, make some paper (or later we found out, biochar).

In early 2014, GTECH began exploring the possibility of making paper of young shoots of knotweed and the older, dried branches for biochar production.

Biochar is a one of oldest farming technologies that most gardeners have never heard of. It it a simple product, (the biochar “technology” has been around for nearly 2,000 years) with a extensive list of benefits. We are primarily concerned with how biochar made from knotweed will better help rejuvenate soil on vacant lots and help vegetation grow. Its viability is currently being tested.

Albert Pantone, an East End-based fiber artist, will be leading the paper production paper portion of the project. This summer we will host workshops for interested community members, scientists, gardeners and artists who want to learn how to make paper.


We would like to give a special thanks to our partners. Albert Pantone for lending us his paper making expertise and for being such an involved community member. Also to Chatham University for conducting soil samples. Thanks to Alison Etheridge from Duquesne University for conducting marketing research and bringing hands-on expertise on making biochar from her experience in the Peace Corp. Also to Brian Verdi from Duquesne University, who researched the feasibility of using Knotweed as a raw material for biochar production and researching practical applications of it.