Posts Tagged Autumn Olive
For Earth Day: Love the natives; hate the invaders.
Posted by piedmontgardener in Favorite Plants, Invasive Exotic Species, piedmont gardening on April 22, 2013
I’m reasonably certain that’s a Spring Beauty (Claytonia virginica). This early-blooming spring ephemeral wildflower usually starts blooming just a day or two before the American trout-lilies in a moist woodland at the NC Botanical Garden in Chapel Hill. I’ve always thought them to be exquisitely delicate and lovely, and they were on my “Add Someday” list for our five acres of Piedmont chaos. No longer.
Yesterday, Wonder Spouse and I stumbled across two tiny blooming specimens in the middle of our currently moist floodplain. We haven’t mowed there yet, because we’re still picking up fallen limbs from winter storms, which is probably why it managed to push out flowers in time for us to notice. The Spring Beauties at the NC Botanical Garden grow in what becomes deep shade as the floodplain canopy trees above them leaf out. Our volunteers are in a sunnier locale, near a large pine, perhaps enough to give them afternoon summer shade. From this difference, I conclude that Spring Beauties require moisture more than shade.
Our volunteers likely found their way via floodwaters from our little creek, which is only about ten feet from their growing site, in an area that overflows whenever the creek waters escape their banks. We could not be happier to have this native join us: another native to love.
Wonder Spouse and I spent several hours wandering the floodplain/wetland habitats of our yard yesterday, because this is the time of year when their health is demonstrated by the ecological diversity of the beautiful native plants that thrive in the muck. Indeed, there is much to love in a healthy native wetland. There’s also much to worry about: invaders. Non-native, alien species remain the number two threat to healthy native environments world-wide (after outright destruction), and in my yard, we battle invaders constantly.
From Beauties to Bullies
Some battles are nearly hopeless. Japanese Honeysuckle and Japanese Stiltgrass are so aggressively pervasive in our North Carolina woodlands and backyards that the best most of us can do is to try to keep them out of selected areas — a favorite flowerbed perhaps, or a beloved tree, in the case of Japanese Honeysuckle.
Battles Still Worth Fighting
In my wetland/floodplain areas, the invader we are still fighting — so far, successfully <knock wood> is Chinese privet. This evergreen, common hedge shrub of older homes produces blue-purple berries that birds adore. They distribute seeds everywhere, but the privets are most dangerous to floodplain/wetland environments. In some areas in eastern North Carolina, the understory composition of vast acres of wetlands has been completely overtaken by invading privet. Because these non-natives are evergreen, they outcompete wildflowers, shrubs, and tree seedlings for light and other resources. Eastern North Carolina wetlands are becoming biological deserts, consisting of nothing but privet beneath canopy trees. When those trees die, no seedling trees will replace them, because they can’t compete successfully with privet. Eventually, our eastern wetland landscape will consist of miles and miles of nothing but privet.
Plant invaders are overlooked by most folks, because their progress is slower than, say, invading Emerald Ash Borers or Sudden Oak Death. To the untrained eye, green is green. But native animals and plants know how critical the differences are. If you love your southeastern Piedmont landscape, you should know too.
Whenever Wonder Spouse and I walk around our yard, we keep a sharp eye out for Chinese privets (Ligustrum sinense). Seedlings appear constantly, typically beneath trees, where birds deposit the seeds after feasting on privet fruits elsewhere. Yesterday, we spotted several larger shrubs that we had somehow overlooked previously. Greens blend together, and in crowded thicket areas (left for animal nesting habitat), a privet sometimes escapes our notice — for a while. I am especially vigilant in my hunt for this species in my wetland and along the edges of my creek. These areas are most vulnerable to this devastating invader.
While hunting privet yesterday, I was disturbed to discover that some of the Autumn Olives (Elaeagnus umbellata) invading the top of our hill have made it to the floodplain and wetlands. This pernicious invader has taken over many acres of upland environments, such as ridge tops, in my part of the southeastern Piedmont. This species and its close cousins (E. angustifolia and E. pungens) are all non-native shrub species. All are very bad news for the local environment, despite the berries that birds eat with gusto.
Wonder Spouse grabbed his trusty Weed Wrench and went to work on the invading Elaeagnus shrubs, pulling out long-rooted invaders from mucky ground, accompanied by a rather satisfying sucking sound.
Note the flowers just opening on this one:
This was a larger one that put up considerable resistance before Wonder Spouse prevailed:
A New Enemy
And, there’s more bad news for my little patch of Piedmont: Asiatic Hawksbeard (Youngia japonica). This relatively recent annual invader was introduced by the nursery trade. It was probably inevitable, given the number of plants from nurseries that I’ve added over the decades, that this horrifyingly aggressive invader would appear on our property.
To the casual eye, the basal rosette of jagged leaves of Youngia looks quite like that of a Dandelion. But if you look a little more closely, the dangerous differences become evident. It sends up clusters of small yellow flowers on bloom stalks. Dandelions only produce one, much larger yellow flower per stalk. Seeds of Asiatic Hawksbeard look somewhat like those of a Dandelion; they are both attached to white tufts that allow them to float far on breezes. But Hawskbeard seed tufts, like its flowers, are much smaller — and uglier — than those of Dandelions.
I know you’re thinking this is just one more lawn weed, right? Not really. Unlike our common non-native weeds — Dandelion, Henbit, Chickweed, Lambs Quarters — Asiatic Hawksbeard spreads much, much more aggressively. Its basal rosettes are dangerously easy to overlook, and now the experts tell me that they are moving into our dwindling natural areas. In these diminishing patches of native forest, Asiastic Hawksbeard is joining Japanese Stiltgrass, Japanese Honeysuckle, and larger invaders in displacing native wildflowers and other small native plants. Every new invading plant means more competition for food, light, and water for our natives. With no natural predators to slow them down here, their eventual takeover seems a near certainty.
Asiatic Hawksbeard has a taproot similar to that of a Dandelion, and if you don’t get it all when you pull it, the plant will regenerate. Also, you can’t just toss pulled Hawksbeards onto your compost pile. Flowers and even nearly-open flower buds finish their cycle and release seeds into the environment even after they’re pulled. Knowing this, I spent many, many hours last year carefully digging out this new invader from my yard wherever I found it. Every plant went immediately into a trash bag, which I tied and left in the hot sun to fry before adding it to my trash can. Despite my efforts, the Youngia is much more pervasive now that it was last year. And I’m seeing it in all parts of my yard now, whereas, last year, it was confined to only certain areas. The basal rosettes have a distinctive yellow cast, and the leaves are slightly fuzzy. I’ve become quite adept at spotting them. Next winter, whenever we spot one, Wonder Spouse and I are planning to resort to treating them with Round-up. Wonder Spouse and I are ridiculously outnumbered, and this is a war we don’t want to lose.
Reasons to Keep Fighting
And there is so very much to lose. On this Earth Day, let me leave you with a few positive images from our still-healthy wetland, where the wildflowers and other plants are wakening to warming weather with enthusiasm for another growing season.
On this Earth Day — and every day — I will continue to love the diverse and beautiful native species that bless my property. And I will battle non-native invaders as long as I can breathe. Clean water and air can’t exist without the help of healthy native environments — especially wetlands. Do your part today and every day by eradicating invaders in your yard. To learn more about invaders in Southeastern North America, start here.