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.

End of Spring Invasive Shrub Treatment

There are two periods in the year when I aggressively attack the invasive shrubs at Blue Jay Barrens. First there is a spring season, which typically begins sometime in February and continues until about the end of April. Next comes the fall season, which begins sometime in August and runs through mid-November. These two periods are ideal for cutting and spraying shrubs because the shrubs are easy to locate and there is minimal chance of trampling nontarget species while searching out the invasive. Today is the last rain free day forecast for the near future, so I’m going to make good use of the dry weather and finish up my spring season cutting and spraying. The photo above shows the most common four invasive shrub species that I deal with. From the left we have Multiflora Rose, Bush Honeysuckle, Autumn Olive, and Japanese Barberry. Those four specimens are also representative of the size that I’m currently treating.  The hand pruners on the right have a total length of 8 inches. At least 75% of the invasives I now find are less than 12 inches tall. I’ve finally run out of the big guys.

I’ve also found about a dozen plants of the European Privet. I don’t know where the seed source is for this invasive, but I do know that there are no mature shrubs of this species within the Blue Jay Barrens boundaries.

The source of seed for my four top invasive shrub species is no mystery. All I need to do is look across the property line fence in any direction and I will see mature specimens of each of the local invasive species. I get particularly depressed at this time of year when the fragrance of Autumn Olive blossoms is so heavy in the air it almost makes you choke.

Today I’ll be walking the Indian Grass fields looking for Multiflora Rose. It takes two or three years for the rose plant to grow large enough to be seen in the dead tallgrass stalks. A quick walk through the fields in the spring is all it takes to find the few roses that managed to take hold there. Fortunately, even though some of the plants get rather large, the roses don’t flower until they’ve pushed up out of the grass and into the sunlight. My annual field sweep insures that none of the plants mature enough to produce seed, and that is the key to control.

It’s a little bit discouraging at this time of year when you stop to think that seeds from invasive shrubs will be forever dropped onto Blue Jay Barrens.  It helps brighten my mood when I revisit cleared areas previously choked with invasives. A photo taken eight years ago from this location would have produced nothing but a close-up look of a solid screen of Multiflora Rose leaves. Now this site cycles through a variety of native species each year and has a growing population of native rose species moving in. By August I’ll be ready to tackle invasive shrubs again, but for the next few months it’ll be nice to do something different.

Advantage: Invasives

Invasive shrubs manage to overwhelm many ecosystems by more effectively exploiting the resources available in their environment.  They are currently busy demonstrating one of the characteristics that allows them to claim such a dominant role in any ecosystem they occupy.  Plants use sunlight captured by green leaf area to fuel the photosynthetic process that supplies the energy needed for plant growth and reproduction.  Invasive shrubs, like the Bush Honeysuckle shown above, produce leaves quite early in the year and hold those leaves into late fall.

Our native plant species have evolved a sequence growth that allows each species to capture the sunlight necessary to its survival.  Spring wildflowers generally complete their growth early in the year and by the time the trees have developed their leaves, the early plants have stored the energy they need to produce seed and carry on to the next year.  At Blue Jay Barrens, the leaves of invasive shrubs develop in advance of most of the early wildflowers and deprive the native species of their needed sunlight.  Eventually, the invasives form a solid thicket and the natives disappear.

The vining Japanese Honeysuckle does the bush type one better.  In some years, the previous year’s leaves remain green through the winter.  The leaves to the upper left are from last growing season and the rest are new to this month.  As long as the leaves are green, photosynthesis can occur.  While native plants are in their winter dormancy, Japanese Honeysuckle grows continually stronger and more able to compete for a place in the landscape.

Autumn Olive is quick to take advantage on the slightest winter thaw.  The long leaf season of these invasives allows them to put on some tremendous growth.  This four foot tall specimen represents only two years of growth.  In that short time it went from a seedling, barely reaching above the leaf litter, to a major producer of shade.

These leaves are the result of about two weeks growth.  The growth will soon begin to elongate into the production of new stems.  The shrub could easily double its height and quadruple its width before the end of this growing season.  That is, it could have if I had not cut it down and sprayed the stump with herbicide.

Seedlings may take a couple of years to develop a root system capable of sustaining rapid top growth.  This seedling managed to hold onto one of its leaves for the entire winter.  The benefits from this one leaf have probably greatly increased its competitive edge.  If I hadn’t cut and sprayed this little guy, it could have reached over two feet tall by the end of summer.

Multiflora Rose is another that is quick to put its leaves into play.  Frosts and freezes may cause some leaf damage to these shrubs, but the damage is generally restricted to shrubs growing in the open.  Shrubs growing beneath the canopy of taller plants are often protected from frost damage.  If some leaves are killed, they are quickly replaced.  All of these species are highly susceptible to a cut stump application of glyphosate during this early growth season.  I usually carry my pruners and spray bottle with me everywhere I go during this time of year.  Fortunately, I am now only dealing with newly arrived invasives, so a pair of hand pruners is all I need for the job.

End of Season Invasive Treatment

On the last day of November, I wandered through this little patch of ground near the house in search of invasive shrub seedlings. This is a prime loafing area for many of the birds that routinely visit my feeder. They are joined by some notorious fruit eaters, such as Robins and Cedar Waxwings, that make frequent visits to the pan of freshwater kept near the bird feed. A result of all of these loafing birds is a never-ending supply of invasive shrub seeds falling with the bird droppings.

The treatment area is just slightly less than half an acre, but I managed to accumulate a nice little pile of cut shrubs. Each shrub was cut at ground level and the stump was treated with a 41% glyphosate spray.  The haul consists primarily of Bush Honeysuckle with a few Autumn Olive and Multiflora Rose mixed in.

Most of the shrubs are quite small, but a few push up close to 3 feet in height. The plants in the center of this group are Bush Honeysuckle, flanked on the right by a single Multiflora Rose and on the left by a lone Autumn Olive.

Temperatures this fall have been considerably warmer than normal, so many of the invasive plant species have remained green. With most everything else displaying some shade of brown, it’s easy to spot these invaders in the landscape. Autumn Olive and Multiflora Rose have now lost all or most of their leaves. This Bush Honeysuckle looks as green as it did midsummer.

I called a halt to this season’s invasive shrub treatments on November 30. Bush Honeysuckles will soon join the other shrubs and shed their leaves. It’s pointless to search for these small invasive shrubs when they have no leaves. A leafless seedling is practically invisible, as demonstrated by this Bush Honeysuckle, the same plant as in the previous photo, hand stripped of its foliage. Larger individuals can certainly be dealt with now, but I seem to have eliminated all of the larger invasive shrubs from within the Blue Jay Barrens borders.  

Treating Invasives

I took advantage of the mild weather during the first half of November to search out and eliminate some invasive shrubs.  Most of what I find now are young plants that have not matured enough to produce seed.  Birds will continue to bring in fresh seeds, and plants resulting from those seeds are what I am primarily dealing with now.  Birds that left seeds on this spot had a varied diet that resulted in a cluster of my four primary target plants.  Clockwise from upper center are Autumn Olive, Multiflora Rose, Bush Honeysuckle, and Japanese Barberry.

Japanese Barberry is a recent invader of Blue Jay Barrens and has not become very well established.  By the time the first Barberry plants began showing up, I had already begun dealing with invasive shrubs.  Only a few got up to fruiting size before they were discovered and removed.  This species is easy to control by stump spraying with glyphosate.  Even a maximum recommended dilution of the chemical is enough to kill the roots.

I’ve still got a couple of small patches that continue to produce a wealth of new Bush Honeysuckle plants each year.  Fortunately, the glyphosate stump treatment quite effectively kills this invader.  It’s discouraging to annually deal with so many new plants, but the sites are small and the number of plants continues to decrease.  Five years ago, the new Honeysuckle growth here was thick enough to block the view of the ground, so I am making progress.  I have to remind myself of that fact each time I work here.

Only one larger Honeysuckle specimen was found this year.  It was roughly six feet high, but was not old enough to produce fruit.  Last year, this shrub would have been only two or three feet tall and would have been easy to miss in its position on the lower slope of the creek bank.  I don’t mind finding an occasional large plant, as long as I catch it before it has a chance develop fruit.

Autumn Olive is the most difficult shrub to control at Blue Jay Barrens.  I use a stump treatment of undiluted glyphosate 41% concentrate solution.  This method is quite effective as long as the plant being treated is displaying healthy, bright green leaves.  Once the leaves begin to yellow and drop, it becomes more difficult to get a good kill.

Older, fruit bearing  Autumn Olive specimens can be killed by the same stump treatment, but there is a high likelihood of root sprouts appearing the next growing season.  It may take a couple of years to eliminate the sprouts.  Seedlings also tend to recur for several years following the death of the large shrub.  Birds feeding on the fruit, drop some of the seeds from the previous day’s feast.  Some of these seeds are ready to sprout immediately, while some may wait through a few seasons before germinating.  The good thing is that no matter where the new plants are coming from, their numbers tend to lessen with each passing year.

Autumn Olive can grow so rapidly that they sometimes seem to appear from nowhere.  This area of Indian Grass was mowed last November.  Small Autumn Olive plants, hidden in the thick grass, were cut off a few inches above ground level.  With a healthy root system already in place, the regrowth from those cut stems reached six or seven feet high in one season.

This is what the base of that plant looked like.  The dead stub in the center of the stem cluster is the single stem that was cut off last year.  It’s obvious that mowing is no way to control Autumn Olive.

To effectively treat young Autumn Olive, you must cut the stem flush with the ground.  The problem is that the stem you see may not be rising directly above the root.  Autumn Olive commonly produces a horizontal stem that later gives rise to the aerial branches.  This horizontal stem is often hidden by thatch or neighboring plants.  In the photo, the stem to the left was attached to the root and the vertical shoot emerged three inches away.  Cutting and spraying at the base of the vertical shoot would most likely not kill the plant.

I am also beginning an assault on the invasive Crown Vetch.  It was planted along the road about 40 years ago, but only recently has it begun to show up out in the fields. 

I was going to spray the Autumn Olive with Clopyralid this summer, but neighboring vegetation made it impossible to get the spray through to the vetch leaves.  Instead of spraying, I went around and identified the locations of all infestations, about ten in all.  I mowed them this fall and will do my spraying next spring when the vetch begins growing.  I guess I don’t have to worry about running out of invasives to deal with.

After Mowing Spray Activity

I’ve added a new species to my list of woodies that readily colonize an open field.  Persimmon, Diospyros virginiana, has aggressively infiltrated the field, growing with such vigor that it has produced fruit in just five years time.  That fruit is full of large seeds ready to claim their place in the field. 

These Persimmons were the only woody species that grew so large in five years that I chose not to run them over with the mower.  The mower would have taken it, but the blade gets worn enough on small stems.  There are a very few mature Persimmon trees scattered about the property, but none are especially close to this part of the field.  I suppose some animal stuffed with Persimmon fruit spent a relaxing time here in the corner of the field and dropped the seeds around.

Most of the woody plants were small and easy to handle.  There were several dozen young Multiflora Rose plants, some with multiple stems radiating from a central root.  The mower shortened the stems, but the plant still needs to be trimmed down in order for the herbicide spray to be effective.

By sliding my loppers in beneath the stems, I can cut the rose at ground level where the plant is concentrated into a single trunk.  Glyphosate is easily applied to the single cut and will effectively kill the plant.

Yucca filamentosa is beginning to show some aggressive invasive tendencies.  The basis for the name is easy to see from the fibrous filaments exposed atop the shredded leaves.  These plants are obviously growing from seed, but Yucca plants have just a single pollination agent in the form of a Yucca Moth.  Without the moth, the plant is not pollinated and no seed results.  I have been looking for 25 years to see a Yucca Moth visiting the Yucca flowers and have yet to find one.  Apparently I’ll have to try even harder.

At first glance the Yucca basal rosette appears to represent a single plant.  Actually, the clump is composed of numerous plants and slowly spreads to occupy more and more space.

Each stump gets a little squirt of glyphosate.  This is my first year treating Yucca stumps in this manner, so I’ll have to wait until next spring to see if the plant is completely killed.

The mower blade shatters the stumps of most woody plants.  Spraying herbicide on a stump in this condition is usually ineffective.  Those splayed ends will die from dehydration and the glyphosate will not move into the living tissue.

More likely, the stump will sprout new stems at ground level.  This Ash stump looks to have been cut off and left untreated when the field was mowed five years ago.  The most effective way to eliminate this tree is to cut below the sprouts and apply herbicide.

I settled on November 1 as the beginning of my field mowing season because woody plant species seem particularly susceptible to a stump treatment of glyphosate at this time of year.  This treated Ash will not be growing again.