Fall Project 2017

Each year during September and October, I tend to embark on a large scale management project at Blue Jay Barrens.  This year I worked to systematically eliminate all invasive shrubs from a 16 acre block that was historically used as a crop field in the early 1900’s.  Since all invasive shrubs of seed bearing age appear to have been eliminated from the property, I thought the next step should be to aggressively pursue the youngsters.  My primary problem shrubs are Multiflora Rose, Bush Honeysuckle, Japanese Barberry and Autumn Olive as shown in the lineup in the photo above.  I also find a few Privet and a couple of Winged Wahoo.

My project area sits on a long south facing slope and is a roughly rectangular shape measuring 900 by 800 feet.  The area is currently a patchwork mix of large Eastern Red Cedars, mixed hardwoods, and barrens openings.  I began work at the east property line and worked my way west in a series of strips paralleling the fence line. Each strip ran from the creek up to the hill top, an elevation difference of about 140 feet.  The neighboring property has a growing population of invasives and birds bring plenty of seeds across the property line.  Invasive shrubs were especially prevalent within 100 feet of the fence.

To make my search as thorough as possible, I produced a grid pattern by using marking flags to establish the strips and to show the corners of each cell within the strip.  Strips were about 20 feet wide and each cell was about 35 feet long.  This resulted in around 1,000 cells developed within the project area.  I began by establishing two strips using three lines of flags; one red, one blue, and one yellow.  As I completed each strip, I would move the line of flags west to make a new strip.  Within each cell I would walk a line about three feet in from the side, cross over at the end and walk about three feet in along the other side, and then travel up the center until I reached the next cell.  There’s no place within that 16 acres that I wasn’t within a few feet of while searching.  Every invasive shrub found was cut off at ground level and the resulting stump treated with glyphosate.  Most of the treated individuals were less than two feet tall.  If I could see it, I would treat it.

Of course, that doesn’t mean I found every invasive shrub there was to find.  Surrounding native vegetation often hid the invaders.  Dappled sunlight could also be effective camouflage.  Despite these obstacles, I drastically reduced the number of unwelcome shrubs.

Even shrubs that appear impossible to miss can be hidden from view.  This Bush Honeysuckle could not be seen from the other side of the tree.

The concentration of invasives was greatest beneath trees used by roosting or resting birds.  The photo above shows an Autumn Olive, a Bush Honeysuckle and a Multi-flora Rose, three of a larger collection of similar specimens all inhabiting the same small area of ground. 

The cause of the infestation was a large Sycamore, the trunk of which can be seen here in the background.  Flocks of Robins and Cedar Waxwings seem to spend considerable time in the upper branches of towering Sycamores, often after making a large meal of fruits from surrounding shrubs.  While resting, they are also dropping seeds into the fertile soil beneath the tree.

It’s common to find a clump of seedlings that has developed on the site of a seed filled bird dropping.  This jungle of Autumn Olive seedlings resulted from a single bird drop.  

The seedlings must now compete among themselves for survival.  The plants at the edge of the cluster stretch out to capture sunlight.

The clump may appear to be spread over a rather wide space, but clipping the tops reveals that all stems are originating from a single small spot.

Invasives were cut and treated in this area in a slightly less intensive search conducted four years ago.  These two Bush Honeysuckle stems and the stump from which they were cut are a result of that management effort.  I was concerned when I found many Bush Honeysuckle seedlings growing in a roughly 10 foot diameter circle centered around the dead stump.  Could seeds from fruit that fell uneaten to the ground germinate after several years of natural stratification?  If so, this could cause another complication in the battle to control these invasives.  Hopefully, this is just the result of some seed laden birds that just happened to roost above this old bush site.

Multiflora Rose growing on the dry, rocky slopes show an interesting growth pattern.  Most have been growing for many years as indicated by the thick stump found at ground level, but the plants display only the current year’s growth.  Dieback due to harsh conditions seems to be a perennial problem for these roses.  That doesn’t stop them from trying anew each year.  The plant shown above has one live stem produced this year, one dead stem produced last year, and numerous scars on the stump from previous years.

Multiflora Roses also have a habit of sending out a horizontal stem that stays hidden from view.  Cutting and applying herbicide above this branch could cause the treatment to fail and the rose to survive.  The horizontal branches also have the annoying habit of rooting at the leaf nodes so that a series of individual plants develops along the length of the stem.

I know the property will never be completely free of invasive plants, but it would be nice to reach a point where I could walk around without having their presence so obviously displayed everywhere I look.  As my supply of non-native invasive shrubs dwindles, the populations on neighboring properties is expanding, so new seeds will always be finding their way across the fence.  At one point during my work, I was thinking of one of my favorite books, The Day of the Triffids by John Wyndham.  I didn’t realize it when I read the book for the first time nearly 50 years ago, that the story is basically about a non-native invasive plant species that swarms over the countryside wreaking havoc on the human population.  At one point in the book, Triffids crowded outside barrier fences while the people inside hunted and destroyed any invading seedlings.  It was the scene just outside my fence line that brought that book to mind.  Of course, the invasive plants that I’m dealing with can’t walk and they’re not going to strike me dead if I exhibit a moment of carelessness.  That’s something I can be grateful for as I continue my work.

Spraying Invasives

While I’m out doing work around the property, I carry a small spray bottle of glyphosate herbicide to use on any invasive shrubs I happen across.  Most of what I find, like this Autumn Olive, is only a year or two old and less than a foot in height.

 

Occasionally, I’ll find larger specimens.  This Autumn Olive was three feet tall and growing in a place that I frequently visit. When I find something like this, I always wonder how it was overlooked earlier.

Here’s a possible explanation.  A look at the base of the plant shows evidence of its having been browsed heavily at some time in the past.  Deer often eat young Autumn Olive right down to the ground.  The plant responds by sending up new shoots. 

A few inches above ground is more sign of deer browse.  In between cuttings, the shrub increases its root mass, so regrowth is more rapid after each occurrence.  I could easily have overlooked the plant after its pruning by the deer.  It doesn’t stay hidden forever though.

A clean cut at ground level and a dab of glyphosate applied to the wound means that this shrub will not be making another comeback.  I should clarify that glyphosate was applied only to the stump.  Everything else in the photo is wet because of a rain that had just ended less than an hour earlier.

Some of the Japanese Barberry that I find is more mature than most of the other invasives of similar size.  Being a smaller statured plant, by the time it’s large enough to be easily seen, it could be old enough to produce fruit.  I’m trying hard to keep the invasive shrubs from producing fruit.  I believe that birds feeding on the fruit of invasives will spend most of their time in the vicinity of that food source and are most likely to deposit the seeds of those species in the same area.  I know that there will always be some seeds of invasive shrubs dropped within the boundaries of Blue Jay Barrens, but by denying the birds the opportunity to dine on those same fruits here, the incidence of seed drop will be reduced.

Multiflora Rose seedlings are still commonly found.  The greatest incidence of these seedlings is in areas that once supported thickets of mature rose bushes.  It may take a few years for the collection of seed in these areas to diminish.

Even if I have to deal with a scattering of seedlings each year, these sites are looking much improved over the days when they were a solid Multiflora Rose monoculture.

Large rose canes are now those of native roses.  Native rose seedlings are also becoming more numerous.

Most of the Bush Honeysuckle is small enough to be pulled root and all from the ground.  It’s becoming rare to find any of this species large enough to require a cut and spray.

I was surprised when I pulled on a small Bush Honeysuckle and came up with this previously cut stump.

I remember when this was originally cut two years ago.  A large tree limb had fallen on the shrub and forced the branches to radiate horizontally from the center.  New shoots came up from the horizontal branches as well as the center of the plant.  To assure a good kill, I levered the stump out of the ground and treated the cut roots left behind.  The stump, left on the ground, sent out new roots and began to grow anew.

I set the stump in the branches of a fallen cedar.  This will allow it to dry out and die.

Just to be sure, I cut the sprouts and gave them a shot of glyphosate.  I certainly don’t want to come out and find this thing continuing to grow. 

Japanese Barberry

What a lovely sight to come across while walking in the woods. Well, if your goal is to maintain a healthy ecosystem full of native plants, this is not a lovely sight at all. This is Japanese Barberry, Berberis thunbergii, one of the latest exotic invasives to visit Blue Jay Barrens.

Barberry is a low growing shrub that is hard to notice in the woodland understory. While it is capable of growing in an open field, its preferred mode of entry into a new territory is through colonization of full or open woods.

As they grow, the branches fall outward in a long arch that falls over surrounding vegetation. The branches continue to produce leaves that reduce sunlight penetration. The covered plants begin to weaken and die, reducing competition to the Barberry.

The leaves have a distinctive shape. The broad oval leaf reduces to a long taper down the petiole. There are some chew marks on these leaves, but native insects generally don’t feed on exotic invasive plants. One of the threats to native ecosystems posed by exotic plants is the loss of native insect populations dependent upon the native plants displaced by the invaders.

The bright red berries are eaten by birds and mammals that go on to spread the seeds over the surrounding area. I can see why people found this to be an attractive landscape plant.

Of course we have to add thorns to the mix. I’ve already been scratched and torn by Multiflora Rose and Autumn Olive. I guess Barberry is the next contender. I’d like to think I’ll be able to get ahead of the Barberry and eliminate it, but I doubt that’ll be the case.