Have You Seen This Plant?

The landscape across our watershed has greened up nicely in recent weeks.  The hot, humid temperatures of the last few days and the rain that fell yesterday will undoubtedly lead many of us to spend some quality time outdoors as we pull the inevitable weeds that emerge in carefully planted gardens over the next week or so.  In addition to removing uninvited sproutlings from your planting beds when the temperatures slack off a bit toward the end of this week and you can work outdoors without fear of heat stroke, we'd like to ask that you consider replacing ornamental specimens that were planted in prior years before we realized that they would get out of hand in this region.  There are a number of plants that have been added to gardens by well-intentioned nature-lovers that have inadvertently escaped into the surrounding countryside and now threaten native plant and animal communities here.  Over the next few months we'll discuss some of them, sharing information about why they really don't belong in this region.  We'll try to stay away from the well-known culprits and focus on some of the species that you might be surprised to learn are harmful to local ecosystems.

Miscanthus sinensis

Miscanthus sinensis (aka Chinese silver grass) is a tall, clump-forming, perennial grass from Asia that has been planted in yards and gardens here in New Jersey for several decades.  It is well adapted to growing conditions here and forms effective visual screens around swimming pools and patios and adds striking form to gardens as a speciman planting.  Unfortunately, it has breached garden boundaries and is becoming widespread across our watershed.  You can now see it growing now along roadsides, forest edges and in meadows. 

The silver white
midrib is evident

Miscanthus sinensis spreads by both seed and rhizomes.  It can form large, impenetrable clumps that displace native plants, prevent successional growth of trees and shrubs, and prevent movement of wildlife.  In addition, it is highly flammable and poses a wildfire hazard during dry spells. 

Zebra cultivar

There are over 50 cultivars of Miscanthus sinensis, so identification is not always easy.  You may recognize it by some of its other common names:  Maiden Grass, Zebra Grass, Porcupine Grass, Eulalia, Silver Feather, Chinese Silver Grass, Eulalia Grass and Japanese Silver Grass.   Miscanthus sinensis grows as high as 10 feet and its leaves are typically about 3 feet long and an inch wide with a silver white midrib and sharp tips.  Silvery to pale pink fan-shaped flowers appear in the late summer through fall.

It will take some muscle power, patience and possibly an herbicide to remove Miscanthus sinensis. Its ability to reshoot from pieces of rhizome makes control difficult -- its entire underground rhizome system must be killed in order to prevent regrowth. If you just have one or two speciman plants, digging them up now before they become large as the growing season prgresses is a good option. You'll need to monitor the ground over the next year to dig out any resprouting plants that appear. If you have a screen or border that consists of Miscanthus sinensis, your best bet may be to use a foliar application in the late spring or fall -- lower rates are required in the fall since translocation to the rhizome is occurring at that time.

Andropogon geradi

Andropogon geradi (Big bluestem grass) is a wonderful native alternative that can replace Miscanthus sinensis in your landscape.  Your garden center should carry it -- let the manager know you'd like to purchase more native plants and see if the store will order some for you.

For more information about Miscanthus sinensis and efforts to eliminate it from our region, please visit www.njisst.org, the web site of the New Jersey Invasive Species Strike Team.