Garden Grief Spurred by an Invasive Ground Cover

by Andrea Laine, EMGV

A writer whose work I admire advised me to write about my gardening mistakes. Well, my biggest mistake (of late) was planting an invasive species in my landscape. In my defense, I did not know that Vinca minor (common periwinkle) was invasive in Durham, N.C. In fact, at the time I put three small sprigs of it in the ground in front of my house, I wasn’t all that aware of what “invasive” meant in the plant world.

The North Carolina Botanical Garden defines invasive species as “plants that are not native to the southeastern United States and that have become aggressive invaders of natural areas. ”

I chose a ground cover because the site slopes and, even when mulched, experiences erosion. A ground cover — low-growing plants that spread quickly to form a dense mat – is an effective way to slow erosion on a slope. I chose this particular ground cover because it was familiar to me. I grew it when I lived on Long Island and in suburban Philadelphia. As a bonus, my husband recalled it being a favorite of his mother’s. With variegated evergreen foliage and dainty blue flowers that bloom in the spring and sporadically through the summer – what’s not to like?

myPeriwinkle
Vinca minor in bloom before spring cleaning of the flower bed. Photo by Andrea Laine.

The plants have been in place for five years now and have  expanded rapidly by means of arching runners (technically called the stolon) which root at the tip. I don’t recall precisely when I became aware of its invasive status, but safe to say it was at least three years ago.  And yet, I let them be. Why? I think I was experiencing the five stages of garden grief!

1) Denial – I refuse to believe it is an invasive plant – It is common; sold in nurseries everywhere.

2) Anger – So, what if it’s invasive! It’s attractive and serves a good purpose. Erosion in this spot is not nearly the problem it once was.

3) Bargaining – Dear Mother Nature, I promise not to plant any more of it, if you agree to be okay with me having this little patch. Pretty please?

4) Depression – Okay, this stuff is beginning to act like a bully. It has expanded in every direction and it requires constant trimming to keep it from suffocating the plants around it.

5) Acceptance – Sigh.   

Generally speaking, having a relatively small patch of an invasive ornamental in your garden will not do major harm. If it is at risk of escaping into a natural area, however, it can eventually wreak havoc on the local ecosystem by edging out native species which feed native insects, birds and animals.

Vinca minor’s bully behavior alone was not enough to push me into the acceptance stage. What really changed my mind was reading Bringing Nature Home by Douglas W. Tallamy.

Tallamy writes, “Typically it takes decades for the population of the escapees to build to the point where we start to notice that they have spread from the spots where we originally planted them (Hobbs & Humphries  1995).”

I have observed this at a friend’s property in the Virginia Piedmont region. Vinca minor was planted in the side yard of my friend’s mountain home in the late 1980s. It was a small patch then. Today, it is everywhere – it covers the back yard, the front yard, the other side of the house, across the driveway and up the hillside, down into the woods. It easily covers an acre of natural area and possibly more.

Similarly a single Euonymus alata (winged burning bush) planted on the property decades ago has also overstayed its welcome. For years it was enjoyed – a deciduous shrub with spectacular fall foliage. Fast-forward to today and it is most unloved. The shrub reproduces vigorously underground by the root system pushing out suckers. There are scores of them on a wooded hillside acres large that was once abundant with native raspberry bushes. The competition is visible and the raspberries (which we love to eat) are losing ground.

MH_Berry and Burning Bush
Native raspberry bush in the top right corner is getting edged out by burning bush root suckers that seem to appear overnight. Photo by A. Laine
Euonymus-Compactus
Mature height of a burning bush is 15 to 20 feet.

The best way to avoid invasive plant problems is prevention. The best method for controlling invasive plants is early detection followed by a rapid response.

It is unlikely that I will be living in my home another 30 years, but the introduction of an invasive species to the natural woods around my house is not the legacy I’d like to leave in Durham. I am digging up my Vinca minor.

Resources

Tallamy, D.W. (2007). Bringing nature home: how you can sustain wildlife with native plants. Portland, OR: Timber Press.

About ground covers:
http://www.clemson.edu/extension/hgic/plants/landscape/groundcovers/hgic1100.html

Vinca minor invasive profile:
https://www.nps.gov/plants/alien/pubs/midatlantic/vimi.htm

Euonymous alata invasive profile:  Swearingen, J., C. Bargeron. 2016 Invasive Plant Atlas of the United States. University of Georgia Center for Invasive Species and Ecosystem Health. http://www.invasiveplantatlas.org/

Controlling Invasive Plants – a booklet from NC Botanical Garden:
http://ncbg.unc.edu/uploads/files/ControllingBooklet.pdf

 

 

Avoiding Poison Ivy’s Wrath

By Andrea Laine

Leaflets three, let it be! Berries white? Take flight!

Photo: NCSU Cooperative Extension
Photo: NCSU Cooperative Extension

Truer words were never spoken if you, like me, are among the 85% of the population who are allergic to poison ivy. If you are not sensitive to this plant, consider yourself lucky! And if you are unsure, learn to identify it, and try to avoid it. The entire plant – leaves, stems, flowers, fruits, and roots— is poisonous thanks to a colorless, difficult-to-detect oil called urushiol. The oil can cause a very itchy rash that at its worse can become blistery and last two weeks or more. The rash is not contagious (nor is the fluid inside a blister) and scratching does not spread it, but some areas may show up later than others. And speaking from experience, the rash is quite irritating and unattractive.

Photo: medicinenet.com
Photo: medicinenet.com

Learn to identify the plant
Eastern poison ivy (Toxicodendron radicans) is a woody perennial vine, or small shrub that belongs to the Cashew (Anacardiaceae) family. It reproduces by underground rhizomes and seed. I frequently encounter it as leafy shoots about ankle high. It has compound leaves that occur in threes. The leaflets are elliptic to egg-shaped. The middle leaflet has a long stem. Twin side leaflets have short stems and sometimes are shaped like a mitten. The leaves are alternately arranged along the main stem as illustrated below.

9iRRGEkie

Poison ivy’s appearance changes with the seasons:

  • In summer the leaves are green. Flowers are small, yellowish green, in clusters of 2 to 6 in lower leaf axils.
  • In fall, the leaves change to autumn colors and tiny berries begin to form. When the leaves drop, the berries get plump and turn white.
  • In winter, the plant is most noticeable as a thick brown vine with shaggy rootlets creeping up a tree.
  • In spring, new leaves appear, shiny and red with green venation.
Poison Ivy in Autumn Photo: NCSU Extension
Poison Ivy in Autumn
Photo: NCSU Extension
Poison Ivy in Winter Photo: NCSU Extension
Poison Ivy in Winter
Photo: NCSU Extension
Poison Ivy in Spring. Photo: poison-ivy.org
Poison Ivy in Spring.
Photo: poison-ivy.org

Poison ivy prefers moist, deciduous forests, but it is resilient and can grow anywhere – a sunny meadow, fence rows, sand dunes at the beach, a parking lot.
Protect yourself
Poison ivy is most dangerous in spring and summer when oil content is the highest. Where I frequently weed, a native woodland habitat, it is hard to avoid encountering poison ivy. Thus, protective clothing is essential. I wear long pants, a long sleeve button-down shirt over a t-shirt, rubber boots or washable sneakers, tall socks, and gloves.

Rubber gloves provide the best protection, but only if you are willing to toss them in the trash after one wearing. If I have an old pair, I will use them, especially if I intend to hand-pull the ivy. Otherwise, I wear one or two sets of latex gloves over my gardening gloves. This way I can peel away and replace the outer layer (with a fresh set of disposable gloves) anytime I need to do something else with my hands, such as wipe sweat from my brow, pick up a gardening tool, or switch to another activity. Long plastic bags like the kind bread loaves come in are also effective to protect hands and arms, though harder to work in. Before I learned to be mindful of poison ivy’s presence while gardening, I would innocently transfer the toxic oil to my neck or face.

gloved hand

Post-exposure prevention
Cleaning up properly after exposure is also important because the oil generally binds to the skin within 30 minutes and can remain active for months on objects like gardening tools and clothing.

I pack three plastic grocery bags in my gardening tote:

  • One is for the outer and inner layers of disposable gloves.
  • Any small tools I have used get dropped into a second bag so they can be cleaned with rubbing alcohol later.
  • Yet another bag is for my long-sleeve shirt because undoubtedly the sleeves have brushed against the ivy. As I remove the shirt, I pull the sleeves inside out to contain the exposed area.

Once all sets of worn latex gloves are in a bag, and before I do anything else, that bag goes into the nearest trash can. My gardening gloves go into the bag with my shirt. Once indoors, I remove the rest of my clothing, being sure to also turn my pants inside out, so they are less apt to come in contact with a surface other than themselves. Launder everything including gardening gloves and sneakers in cold water and detergent. Do not use warm or hot water as it may spread the oil.

Even if you have worn protective clothing, scrubbing your skin afterward with cold water and soap is recommended. There are special over-the-counter cleansing agents, such as Tecnu and Zanfel, to aid in the removal of urushiol from skin. There are protective lotions, too, (Ivy Shield and Ivy Block) that may reduce the risk of a poison-ivy rash by delaying the penetration of the oil. These are applied before exposure.

Numerous topical ointments are available for treating poison ivy symptoms. If a rash develops despite your best preventative efforts, consult a physician or pharmacist for appropriate treatment.

A positive note
Poison ivy does have some redeeming qualities. It gives abundant food and shelter to wildlife which, by the way, are not negatively affected by urushiol. Deer and rabbit munch on its leaves. More than 55 bird species are known to consume poison ivy fruits. It is pollinated by bees; There is no urushiol in the nectar.

Here’s an interactive QUIZ to help you identify poison ivy.

A future article will explore methods to control poison ivy in the landscape.