Arlington, MA Invasives "ArMI" Army's Boletim

In late summer the ArMI sounded an alarm at Turkey Hill (Arlington). A large black swallow-wort patch has been expanding at the water-tank top of the Gay St. Trail: https://www.inaturalist.org/observations/90784659 We now have good news about the other end of the trail, at Gay St.

Native Roundleaf Greenbriar (Smilax rotundifolia) is forming abundant wild-life habitat. https://www.inaturalist.org/observations/100065401 . Smilax rotundifolia is a green, crawling vine with spaced out thorns that can tangle within itself and other plants, and climb with small tendrils. It does not endanger mature trees, as Oriental bittersweet does. The open, tangled vines allow light to permeate the shelter beneath, forming a protective canopy for nesting birds and small mammals.

Smilax rotundifolia is a very important food plant in the winter when there are more limited food choices. Examples of wildlife that eat the berries and leaves in the late winter and early spring are Northern Cardinals, white-throated sparrows, white-tailed deer, and rabbits.

The human palate enjoys roundleaf greenbrier as well. Young shoots and uncurled leaves and tendrils can be eaten raw or cooked. The young shoots are reported to be excellent when cooked like asparagus. [6] The young leaves and tendrils can be prepared like spinach or added directly to salads.[6] The roots have a natural gelling agent in them that can be extracted and used as a thickening agent.

Greenbriar adds resilience to a woodland, as it vigorously regrows after a fire, yet regains a proper balance when the woodland's regrowth catches up.

1. Peterson, L. A. (1977). Edible Wild Plants. Houghton Mifflin Company. p. 198.

At the beginning of summer, the entrenched knotweed at Hill's Hill and Fields in Arlington, MA seemed a formidable task. https://www.inaturalist.org/observations/81864810

Inexperienced with removing this stuff, we picked around the edges. We discovered black swallow-wort growing deep underneath in its shade ... and removed that: https://www.inaturalist.org/observations/81863330 . We found oriental bittersweet lurking within, and around the edges. We dug that up too, as best we could with the knotweed stand still standing:

• Oriental bittersweet under the knotweed: https://www.inaturalist.org/observations/81865860
  
• … and on the edges: https://www.inaturalist.org/observations/85680894
  

We liberated two native black walnut trees in the process.

Then an interested Arlington Conservation Commissioner demonstrated technique. Dig under the root ball and pop. He had experience removing a stand single-handedly further down the bike path and in Arlington's Great Meadows. We gathered courage and decided to tackle the summer's spill-over growth on the basketball court side of the fence. A couple of hours work and things were looking pretty good: https://www.inaturalist.org/observations/98899544

It was the exuberance of youth however that ended up demoing the "old-growth" knotweed canes. We are ever indebted to the young people who took on the task during a bike swap at the Ryder St. DPW yard. With the canes down, somehow the task of digging wasn't quite so daunting, though the solid, concrete-like root knots of a mature stand do present a formidable infrastructure. Slowly the roots are emerging, being bagged and incinerated. We even snagged orange bittersweet roots buried deep with in the former knotweed stand. Four bags the first day. Eight bags the second go round, and how many pounds later? We know we're in this for the long haul. Next year, and the next.

But now we have a strategy for starting the task: 1) get associated invasives out from under and around the edges to lessen the seed bank by at least one year; 2) find a group of enthusiastic young people to hack at the canes; 3) then start digging furiously before the ground freezes (be sure to collect ALL roots and black-plastic bag them for incineration); 4) plan to cut canes to the ground once a month after that ... REPEAT and vary the strategy as needed to suppress regrowth. We hear layering cardboard or plastic might help with that. Perhaps we can even supply paper-making artists with canes for community art next year!