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.

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.  

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. 

A Chore that Goes With Walking

Many of the non-native invasive plants tend to green up early in the year.  This aggressive growth habit is part of the reason they are so successful at claiming new territory.  By the time most of the native species are beginning to grow, they are already overshadowed by the invasives.  This Bush Honeysuckle is a good example of an invasive plant that gets an early start.

There’s also a disadvantage to being an early greening invasive plant.  At least that trait is a disadvantage around here.  While out walking, I’m constantly on the alert for those nasty invaders and am instantly attracted to any plant that looks a little too bright green and prosperous.  I pull any small Honeysuckles that I happen to find.  If you have to deal with Bush Honeysuckle, this is the size to hope for.  You can easily remove the majority of the root system and the plant will not grow back. 

There are several species of Bush Honeysuckle and the leaf characteristics vary slightly between species.  They are all invasive.  Fortunately they’re distinct enough for easy recognition as a group.

In areas that once supported mature Bush Honeysuckle, it’s nice to just deal with the little guys.  A one foot tall Honeysuckle has survived to the point where it will easily continue on to maturity, so you can feel confident that you’ve just saved yourself a lot of future work by yanking out the small plant.  The Bush Honeysuckle has a shallow root system that offers almost no resistance when you go to pull.  The next easiest situation is having no Honeysuckle at all.

Little Autumn Olive plants can be given the same treatment.

Autumn Olive is a more deeply rooted plant, so it’s a little bit tougher to pull.  It also has the ability to regrow from healthy root sections.  Fortunately, small plants don’t leave enough root in the ground to make regrowth a problem.  Someone recently asked me if there’s a size at which I recommend cutting and treating the plant instead of pulling.  There is.  If I pull an invasive shrub as hard as I can and it doesn’t come out of the ground, I then feel it would be more effective to cut the plant and treat it with herbicide.

Bush Honeysuckle

Control of woody invasive plants such as this Bush Honeysuckle, progresses in certain phases. Phase 1 is the aggressive elimination of mature specimens. Completion of phase 1 is highly satisfying because you can see an immediate change. You can imagine complete dominance over the invaders and you might find yourself feeling just a bit superior to those who lament the never ending battle against invasive plants. Then comes phase 2 where you suddenly notice a seedling plant of the species you thought was so thoroughly vanquished.

A single seedling wouldn’t be bad, but there’s never just one. As your mind accepts the search image, you suddenly see more seedlings everywhere you look. Then the illusion of dominance over invasive species abruptly crumbles and you remain humbled before an adversary that you had grossly underestimated. The realization that the hard part of the work is still ahead of you can be very disheartening.

This 2011 seedling is healthy and ready to put on some rapid growth over the next couple of years. It’ll still be a while before it matures enough to produce fruit. The objective of phase one invasive species control is to eliminate reproductive individuals. Once reproduction has been stopped, the accumulation of new seeds is almost eliminated. That means that the seemingly unending task of removing new plants will progressively become more manageable.

Bush Honeysuckle seedlings are easy to pull from the ground. I collected a small sample and laid them out in the classic market hunter’s pose.

I believe this to be the parent plant to many of the seedlings. Birds feed on the fruits one day and when they return the next day for another meal, they are highly likely to pass yesterday’s seeds along with their droppings. A fruiting shrub surrounded by seedlings is a common sight.

Bush Honeysuckles remain green and hold their leaves longer into the fall than most native shrubs, so they are easy to spot at this time of year. The positive aspect of this honeysuckle encounter is the condition of the surrounding woods. This woods was thick with mature honeysuckle just a few years ago. The sight of an otherwise honeysuckle-free woods is a positive enough experience to counteract any disappointment I might have felt at the discovery of the one lone mature honeysuckle.