FoAGM JKW Control Project Log



The newly-planted grass area at the JKW site still looks like it's trying to be a lawn, but no signs of new JKW sprouts as of two days ago! -- except around the extreme edges.  Very encouraging.  The area still under the black plastic seems to have some JKW trying to raise it off the ground, but the black plastic seems to be in place.  The cut-cut-cut area has many JKW sprouts and a lot of garlic mustard, some of which I pulled out the other day.  -- DM


New sign approved:

Invasive Plant Control Project

The Friends of Arlington’s Great Meadows (FoAGM) are testing methods of controlling Japanese Knotweed and other invasive plants in this area.  Japanese Knotweed is a persistent invasive whose monolithic growth chokes out all other plants. 

We hope to improve the view and establish a more varied and native habitat.  This project has been approved by the Lexington Conservation Commission.  It does not involve the use of any chemicals.

Volunteers are needed for this effort.  We invite you to join us.

Information is available at our website:


I am very curious to know the status of your knotweed control program in Arlington.  I am up in Vermont, starting a demonstration site in Springfield, to introduce landowners and citizens to knotweed and to encourage them to recognize it and to lend a hand in the control efforts.  I am planning some vigorous and persistent hand-cutting, followed by and in conjunction with the planting of some tenacious natives.  I'd love to know how you did and are doing (I know JK control is usually 3-5 years plus plenty of post-project monitoring) and which plants you ended up using...and when you began planting them.  I am also doing a college paper on knotweed this semester, so I hope it would be okay for me to cite your citizen-science research in my essay. – Director, Black River Action Team


I visited the JKW site this afternoon.  JKW is thick everywhere and 5 feet tall or more in many places, despite the fact that I cut out nearly all of it two or three weeks ago.  The area planted in grass last fall has a relatively small number of short, red, JKW stalks coming up, mostly under 2 feet tall.  I pulled out all such stalks there two or three weeks ago, and there weren't many then, either.  I count this as a success, but it still needs to be attended to. - DM


I noticed that part of the compost pile from about two years ago is very dried out and no longer composting.  Maybe we should uncover part of it and let some moisture get in to help the decomposition process. – DW


I did a lot of pulling of JKW stalks from the grass-seeded area.  They were growing on the lower part of the bank in profusion.  About 75% of the stalks can be pulled up from fairly deep (suggesting they are weakly attached to the remnant of a rhizome), but 25% are clearly part of a strong and healthy rhizome system and simply break off at the surface.  Not, on the whole, a very encouraging development. - JB


One evening late last week, I spent a good hour or more at the JKW site and pulled up every single trace of knotweed that was growing in the area we recently planted with grasses.  There was quite a bit.  I also was able to uproot a fair amount to the right-hand side of the grassy area, facing the meadow.  You can see the considerable amount of material I have pulled over the last four or five weeks on the corner of the black plastic nearest the fence, although it does reduce in size pretty quickly as it dries out.

I went back this evening, and a number of new shoots were already starting to grow up again in the grassy area, just a few days after I had cleaned it all up.  This stuff is unbelievably determined to grow back.

The grass is now starting to grow quite a bit taller, at least in clumps, and no longer has quite the appearance of a lawn.  It will be interesting to see how it develops as the summer wears on.  I have no idea whether the grass itself will have any inhibiting effect on the continued emergence of new JKW shoots -- probably not.

The areas to the right and left of our dig area are certainly giving us a reminder of what this area looks like with a full stand of knotweed.  It must be four or five feet high by now and almost impenetrable.  When Mike comes up with a weed cutter, I will try to take it all down.  I am convinced now that if we don't keep after the side areas long enough to eventually kill them off, the root systems will in short order -- perhaps in just a year or two -- grow right back under the grassy area and send us back to square one.  Maybe the cut-cut-cut method won't work, but I think we'll have to keep trying. – JB


Since our meeting last Tuesday, I have continued to clear JKW from "my" area by hand, leaving the non-invasive plants in place.  I've spent a total of four hours on three separate days since the meeting, and I've done more than half this area.  I think it makes sense to continue doing this for the following reasons:

1.   In that area, there are a number of small sections where NON-invasive species are thriving and JKW has not been growing up through them.  In a few other spots, JKW has sent up one or two small shoots through the thriving plants, but not much.  I don't know if the presence of other species is impeding the JKW, but I think it is possible. 


2.  I have noticed that the JKW shoots in this area are getting smaller and smaller in diameter.  Many are just a quarter inch or so in diameter and are often easy to pull out.  Others are a half inch or larger, but still smaller than the huge ones we used to have.  I think this may be evidence that the energy in the rhizomes is being gradually depleted.   It is also possible that we have about the same bio mass, just more shoots that are smaller.

I have been discouraged about the cut-cut-cut method, but now I see that many stalks are growing up through the grass we planted, especially on the lower half of the slope.  I think cut-cut-cut is worth continuing.  As we discussed at the last meeting, it makes sense to get volunteers to dig out the rest of the root crowns and as many of the rhizomes as is practical. – DM


I was able to get to the Meadow late Sunday evening with the weed whacker and take down most of the stand of JKW growing to the east of the grassy area, by this time ranging from four to six feet high.  In an effort to avoid damage to the machine, I did the cutting at three or four inches above ground level, so things look a bit ratty, but the impact to the plant should be about the same.

Next, I tackled the profusion of new JKW shoots that were sprouting up through the area we planted with grass.  I had completely cleared all JKW out of that area twice before, but in the space of just a week or two it had grown back in profusion.  I was able to almost completely clear the area so, at least for the time being, the grassed-in space is back again to an essentially pristine condition.

While pulling JKW stalks in the grassed-in area, and for some distance outward past its eastern border, I was very encouraged to find that most of the stalks (perhaps about 75%) were quite weakly rooted and that both the stalk and a substantial root component could easily be extracted from fairly deep in the ground.  It almost seemed as if much of the stalks were sprouting not from rhizomes but from small root fragments that were left in the soil when we dug out the larger rhizomes.  If that is the case, then with a fairly regular, and not too strenuous, effort we should be able repeatedly to clear out the new growth in this area until it is largely JKW free. 

At the bottom of the bank, closest to the reeds that are growing at the edge of the wetlands, the JKW was the most deeply rooted, and there were a number of stalks that I could not extract by the roots, even with a good two-handed tug and a lot of back strain (got to be careful with that lower back).  The best I could do was break off the stalks at ground level, so they will inevitably grow back in short order.  We may need at some point to go through this area with the pick mattock and dig out the larger rhizomes that underlie this growth.

Surprisingly, almost all the stalks I tried to uproot to the east of the grassed-in area came up easily with a substantial amount of root mass.  I have piled the stalks and root masses, for the time being, at the top left-hand corner of the black plastic. – JB


I stopped by the JKW area on my lunch break this afternoon and was pleased to see relatively little additional growth in the grassy area since my last effort over a week ago.  (I am assuming that no one did any work here in the meantime.)  I spent a half hour or so pulling stalks, and was able to clear most of that area back out again.  Most of what I pulled seemed pretty anemic, as far as JKW goes.  Good news.

The large JKW root pile seems pretty dead now that we have left it uncovered for a while.  There are some JKW stalks sprouting up out of the back end of the pile, but the rest shows little sign of regrowth.  There was a large garter snake coiled up on top of the pile enjoying the view and warding off all intruders. – JB


I have pulled or cut nearly all of the JKW on the west side of the black plastic, working an additional hour and half since I last reported.  Pieces of rhizome are either on the black plastic or in a black trash bag at the corner of the black plastic.  In the far west portion, some tall JKW plants are still there, but I will deal with them when I return.  I have also pulled out a small number of stalks which were coming up through the newly-planted grassy area. -- DM


Overheard along the bikeway while I was working low on the slope, out of sight:

1.      A young boy, on a bike just ahead of his mother, said "Mom!  Look, to the right!"  "Yes, she said, it's beautiful, isn't it."


2.      One young adult man on a bike yelled to his friend, "That's Great Meadows."


When people do see me, some call out their appreciation for the view. -- DM


I pulled out a bunch of JKW shoots growing on the bike path side of the fence and was pleased to see that they were poorly rooted and came up easily.  Maybe our repeated attacks really are weakening the root systems. – JB


I suggest we give thought to what kinds of plants we want to have grow in the JKW site after the JKW is gone or fairly easy to manage.  In particular, I offer the following principles for your consideration:

1.  We place high priority on maintaining the view.  Thus, sumac and anything else which would block the view would be taken out at some point, possibly as it begins to block the view or when we first we see it.  I assume we would leave the large native dogwood shrubs at the wetland border, but not allow other dogwoods to get large. 


2.  We place high priority on blocking other invasives.  In my opinion, our worst foe in this regard is garlic mustard, which should be taken out whenever seen.  Glossy buckthorn should also be pulled -- we have some seedlings now down near the wetland edge. 


3.  We also give priority to having a variety of plants grow there, not letting one species take over.  In this regard, I suggest we pull out at least some of the large ragweed plants before they begin to take over.  (Allergy sufferers unite!) 


4.  We encourage plants which won't block the view, especially if they are native plants, including: Pokeweed (we have a number of pokeweed plants now, which have interesting flowers and fruits); "Bittersweet Nightshade" or "Climbing Nightshade" (it is growing well on our site, adds foliage and a bit of color); raspberries and blackberries (I would love to encourage these, but they do make it difficult to remove shoots of JKW if they begin to grow within it); Common Evening Primrose (these have a tall, slender shoot on which the yellow flowers grow, but mostly they don't get tall enough to block the view). --- DM 


The JKW site is in the best shape it has ever been.  Go look at it soon -- it may never be this good again!  John weed-whacked the east portion recently.  In the past week, I have spent a total of nine hours working on all aspects of it, including:

- Pulling out new (small) shoots in the grassy area.

- Addressing the shoots along the bottom of the site, both where there is plastic and otherwise.

- Addressing shoots along the wooden bikeway barrier.

- Taking out shoots which ducked just before John's weedwhacker blade went over them.

- Taking out the shoots in the western portion, including extricating them from MF Rose and bramble thorns.

- Removing some MF Rose and as much garlic mustard as I could, the latter being next year's plants.

- Taking out some of the large ragweed plants which are trying to become a mono-culture. 

- Taking out sumac plants while they are small before they block the view.

If you find anything I missed, please feel free to pull it out! -- DM


I did a pretty thorough job of weed-whacking the JKW east of the seeded area last Sunday.  I went fairly far into the woods behind and downhill of the refuse pile.  Perhaps if we get the main area under control we can gradually expand the left and right borders.  It sure would be nice to get a view of the meadow through the trees all the way up from the Brant St. entrance of the bikeway up to our control area. -- JB


I stopped by the JKW area the other night and noticed an interesting phenomenon.  Essentially all of the JKW growth in the grassy area, as well as most of the new JKW that has grown back on the bank to the east since my last cutting three or four weeks ago, has turned yellow and started shriveling up.  I am guessing that the extremely dry weather of late, along with intense sunshine, has proved too much for these relatively tender new stalks.  The worst damage is on the sloping part of the bank where there is the least amount of shade.  But it almost looks as though someone went through and applied a JKW-specific herbicide.  Other types of plants don't seem to be affected, nor does the JKW in the area that has never been cut.  What JKW is left in Don's area to the west also seems somewhat less affected.  Whatever the cause of the phenomenon, it is good to see the JKW in the "cut only" area showing some signs of vulnerability.  I have no idea whether the mortality that appears on the surface is having any effect at all on the health of the rhizomes. -- JB


I stopped by the other evening and found that the JKW on the bank to the east of our replanted site (the "cut, cut, cut side") is still looking yellowed and sickly.  This is in contrast to JKW in areas that have not been touched, which is still, even into mid-October, pretty green and healthy.

Just for the heck of it, I started pulling some of the stalks by hand, starting near the bikeway fence, then moving further down the bank toward the meadow.  To my surprise, I found that in many (though not all) cases, with a little effort and tugging, I was able to pull up large chunks of rhizome and root mass.  The root masses that came up did not seem healthy.  The larger branch roots  were brittle, and some of the masses of smaller roots appeared to be moldy and crumbly.  The soil was pretty wet, and I suspect that made the root masses easier to pull up, but I don't think it would have been nearly as easy if the roots were healthy.  I ended up uprooting perhaps ten or twenty pounds of root mass, which I added to the top of the big pile.

From this discovery, I draw at least a glimmer of hope that the "cut, cut, cut" method really works, and that the JKW that has been subjected to this treatment for several years now -- combined perhaps with the recent drought and hot weather -- is showing real signs of mortality.  The thought occurred to me briefly that we might try to capitalize on the JKW's weakened state by digging up the rhizomes in this area.  I then decided it would be easier, more efficient and more informative to just keep going with the "cut, cut, cut work," which is not too difficult, and see if we can't kill off the plants in the ground, even if it takes a few more years. If we are successful, we could then start working our way east and west. -- JB