|Kudzu on trees in Piedmont Park, Atlanta, GA, from Wikipedia|
Originally introduced into this country by the Soil Erosion Service and Civilian Conservation Corp in 1876 to help control soil erosion problems in Pennsylvania, its rapid growth and luscious foliage made it a favorite to cover shade porches and pergolas in the southern states. It soon became a favorite cover crop because of its rapid growth rate but when left to its own devices and allowed to grow unchecked, it became a veritable menace, destroying everything in its path.
Kudzu has overtaken more than 7.5 million acres in the southern states where it has smothered all low growing plants in its path and covered, broke branches from, and even uprooted trees. Growing up to a foot a day, it doesn't take long to cover an abandoned barn and overtake and damage electrical and phone lines.
|Tall reeds mid left of the photograph, 2009, Ipswich River|
Here in Massachusetts and along the coast extending into southern New Hampshire, a major and pressing problem is the common reed phragmites (Phragmites australis) which has been rapidly and relentlessly overtaking both salt marshes and freshwater tidal basins alike. Its rapid proliferation has caused serious problems along the entire Atlantic coast but it is of particular concern to us as it now poses a major threat to the survival of the 18,000 acre Great Marsh here in Essex County, a critical part of our local ecosystem and marine culture.
There is a subspecies of phragmites that is native to North America, however the subspecies (P. australis subs. Americanus) is a much less vigorous and more easily controlled plant than Phragmites australis subs. Australis, the non-native variety that is now considered a serious environmental threat.
|Phragmites have changed the landscape along the river's edge.|
Phragmites spread and multiply both by seeds (less so) and thick rhizomes (most commonly and aggressively) that are thick, notoriously difficult to kill, and can extend up to 20 inches in depth where they send out innumerable runners. Chopping back the top of the plant does not affect the rhizome which will continue to extend runners and then send up new, denser, more vigorous growth the next growing season. Most importantly, phragmites choke out the other native species which are a critical part of the food chain for local fish and fowl and there is concern about the survival of wildlife and the Marsh if the proliferation continues unchecked.
|Normal plant growth is gradually being overtaken by phragmites along the rivers.|
I first noticed phragmites in 2009 while canoeing on the Ipswich River. (They were certainly here long before that, but had escaped my awareness until then.) I noticed the changing landscape along the river's edge -- the wildflowers and indigenous plants and shrubs were being replaced by a tall grass that formed a dense wall that obstructed the beautiful landscape.
Over the course of two years, large swaths of this noxious weed replaced the natural river habitat in many areas and have completely obliterated the view of the coastal marshes (and everything that used to grow there) along local route US-1.
Even more frustrating is that it found it's way into our own garden this past summer. I went out to weed one of the perennial beds and to my horror,several tall fronds had sprouted in the midst of our Montauk daisies and coneflowers. Digging them out was a major chore and we could not have done it without our spearhead spade shovel.
We abut a meadow that is marshy in the spring and I have seen phragmites growing there, although they are usually mowed down during the twice yearly mowing for hay. Digging them out was a tremendous chore and we ended up digging up and sacrificing several daisies and coneflowers in the process.
|Loosestrife sprouted in a rose bed.|
A common sight along highway medians, roadsides, waterways, ponds, swamps, and meadows, it's pretty lavender color brightens the roadside. But like phragmites, it overtakes wetlands and marshes and has become a major threat to the ecosystem. Also like phragmites, the root system is exceedingly vigorous and once the plants are established, it can be difficult to dig out even with a spade shovel.
Loosestrife spreads primarily by seed which it produdes in voluminous amounts. Easily carried on the wind or by birds, volunteers have been finding their way into our yard from the adjacent meadow for several years.
|Loosestrife popped up unexpectedly in a shade garden|
If you find it blooming in your garden, cut the plant back before it blooms and then dig as much of the root system as you can find. If you miss a substantial part of the root, it will re-grow the following season, so keep an eye out early in the growing season and if you see it sprouting, dig early and dig wide.
Loosestrife has popped up in our shaded cottage bed and among our blueberry shrubs. It also has appeared in our sunny rose beds and along the edge of our property where it abuts the meadow. Since there are large clumps of it in the meadow that will continue to shed seed, all we can do is be vigilant and dig it up as soon as we notice it.
In the case of loosestrife, mowing does help, and when we see it sprouting near the property line, we try to keep it mowed to prevent it from blooming and setting seed.
|Brilliant fall foliage|
The ubiquitous burning bush, Euonymus alatus, can be found dotting the landscape throughout New England.
For decades, its brilliant red autumn foliage and hardy growth habit made it a favorite of landscapers who were designing low maintenance plantings for shopping malls, office buildings, and other places where pollution and drought tolerant shrubs would thrive. The stunning scarlet fall foliage became a favorite of home gardeners as well.
Unfortunately, the burning bush has become a bane of green space and woods alike and many states, Massachusetts included, now restrict its importation, propagation, and sale.
The tendency toward being invasive is primarily a problem where the shrubs have been allowed to naturalize along highways or in pastures and woodlands where they out-compete and eventually replace native plants. When they are planted in urban areas as ornamentals, there doesn't seem to be as much of an issue with them growing out of control, although birds have been credited with spreading the seeds contained in the fall berries.
|Three of our four burning bush shrubs showing vivd green foliage in spring.|
We've been asked many times why we, as responsible home owners and stewards of the land, don't simply dig them up. My feelings about doing so are complicated. The reality is that any robust plant, native or not, can become invasive if not properly monitored and controlled. We saw this first hand when a tall and vigorous cultivar of Mondara (bee balm) overtook one of our cottage beds. It took six years for us to completely eradicate it from our property and reclaim the bed.
While I doubt that I would ever plant another burning bush (or any more bee balm) even in a locale that allowed them (I've never been particularly fond of burning bushes, their status as invasive aside), I see no value to disrupting the existing garden beds and destroying healthy plants that have to date not caused a problem in their present location, especially since they have historically provided nesting places for birds.
Moreover, at least half of the homes and two shopping malls within three quarters of a mile of our home are prominently planted with them. Destroying these four shrubs might make a statement, but to what outcome?
|A large burning bush growing in the cottage garden (2009)|
What we have found very effective and at the same time uniquely attractive is to drastically prune the shrubs in spring, just as the rather inconspicuous blooms are opening. This prevents all but a rare few berries from developing and virtually eliminates the primary way that the burning bush self propagates.
Exposing the inner, larger branches gives the shrub a completely new look and most people who see the shrubs after pruning don't recognize them.
|The same shrub (2012) after we began drastic pruning. Opening up the lower 2/3 of the shrub lightens the visual weight of it in the garden and in so doing, we remove all of the blossoms that eventually would develop into berries and seed.|
|We leave a generous canopy but shape the top. This shrub was formally thickly branched and as wide as the canopy all hte way down to its base.|
List of Invasive Plants - Massachusetts
Newburyport Daily News Article - Phragmites
Wikipedia Entry: Phragmites
USDA Profile: Phragmites; Fact Sheet (pdf document)
National Gardening Association's Weed Library