Projects 2013 - Invasive Shrub Control

I thoroughly enjoyed walking around Blue Jay Barrens during the spring of 2013 and viewing areas that no longer showed signs of their earlier infestation of invasive shrubs.  This old fence row was once choked with Autumn Olive and Multiflora Rose, two non-native plants with a nasty reputation for overrunning and destroying native habitats.

Freed from competition, the native Wild Plums displayed a profusion of blooms.  After several years of battling non-native shrub infestations, it looked like 2013 would be my year to get ahead of the invaders.

My system of cutting Autumn Olive and spraying the resulting sprouts with glyphosate was generating a low volume of total kills, so I changed tactics and began cutting the shrubs during the growing season and applying undiluted 41% glyphosate solution to the cut stump.  With the stump treatment method I’m getting almost 100% kill.  The growth rings shown on this stump illustrate how rapidly a small Autumn Olive can grow into a difficult to handle monster.

In those rare instances when the stump treatment fails to kill a large Autumn Olive, this is the typical result.  Root sprouts produce a thicket in a circle around the dead stump. 
 

This requires each sprout to be individually cut and treated.  It’s aggravating work, but I’ve not had any regrowth follow this procedure.  I’d like to know what conditions cause root sprouting instead of death, but I have run out of large Autumn Olive, so there are no subjects here for future research.

Also aggravating are the clumps of seedlings resulting from a seed laden bird dropping.  It’s sometimes possible to pull these from the soil, but the likelihood is high that the stems will break at ground level and the plant will resprout.  They are also susceptible to a diluted glyphosate solution applied to the leaves.  Since I don’t carry multiple herbicide solutions with me in the field, my default solution is to cut these little guys and spray their tiny stumps.  The biggest problem for me is seeing the pinhead sized stumps.

I was puzzled when I found this Autumn Olive growing from a brush pile on which I had placed several cut Autumn Olive branches the previous year.  I knew that it hadn’t been there before and it was far too developed to be a seedling.

I followed the branches on down to the base and found that it had already been cut.  Then why was it still growing?

Apparently there had been enough moisture in the soil to keep the cut branch alive and it had sprouted roots and kept on growing.  I guess I’ll have to be careful about how I dispose of the cut material.

Early spring is an ideal time to locate invasive shrubs that leaf out in the first warm weather.  While searching for any overlooked Autumn Olives, I kept watch for the new growth of Multiflora Rose.  When found, each was cut and stump treated as described earlier.

Most of the large shrubs that I found were in odd places that caused them to be over looked during my earlier searches.  This particular specimen is one that was growing just a few feet from a frequently traveled trail.  I passed it several hundred times without realizing it was a Multiflora Rose.

That’s because all of the rose leaves were in the tree canopy 30 feet above my head.  The large canes visible at ground level were casually dismissed as grape vines all these years.  Pulling this giant from the tree was a challenge, but it is now gone.  This trait of growing up through the tree branches to reach sunlight is demonstrated by both Autumn Olive and Multiflora Rose.  Even when you know it’s possible, it can still be a surprise.

This is what the roses look like a few days after cutting.  The dried leaves can take a month or more to drop and the canes will remain upright for over a year.

This rose stump was treated in October of 2012 and seven months later shows no signs of life.  I have yet to find any regrowth from treated Multiflora Rose stumps.

I visited the last areas of Multiflora Rose infestation on a weekly basis through the early summer to catch any live plants that I had missed.  This patch was most troublesome.  Dead leaves clearly show canes that were cut and treated.  Two canes covered in white flowers are from still living rose plants in the thicket.  I was a bit scratched up, but when I finally crawled out of that mess, every live cane had been cut and treated.

During September and October 2013 I conducted a search of areas with a history of invasive shrub infestations in order to find and eliminate all remaining individuals of those noxious species.  I had been through all of these areas during the past few years to cut the larger fruit producing specimens.  My goal now was to come as close as possible to completely eradicating the invasive shrubs from the property.  Using alternating lines of blue and red flags to delineate a work area, working one narrow strip at a time, I cut and treated invasive shrubs on 65 acres.

My final 2013 assault on invasive shrubs came in November.  Eight acres of prairie fields were due for mowing according to my rotating schedule.  This activity is normally done in December, but I chose to begin on November 1 while the Autumn Olive and Multiflora Rose were still at a stage of growth that was susceptible to herbicide treatment.  I finished the year feeling that the control of Autumn Olive, Multiflora Rose, Bush Honeysuckle and Japanese Barberry at Blue Jay Barrens was now a maintenance issue.  I know that birds will still carry seeds onto the property and I’ll have to deal with the new shrubs that sprout, but at least for a few invasive species, I feel I am now in control.