Editor’s note: This is the second post in a series about bird-friendly native gardening written by Wendy Diaz, EMGV. The third and final post, a plant list, will appear next week.
After a visit to my yard by representatives from the New Hope Audubon Society, I resolved to rid my garden of invasive species. My goal is to achieve Platinum Certification and, consequently, invasive plants cannot cover more than 10% of my property; an improvement from the Gold Level I received in August. A helpful guide on how to plan and implement a more bird-friendly yard, by selecting native plants that suit your needs as well as birds, is provided by the Going Native website1. A particularly useful tool is the plant selection guide that helps you select plants that fit your gardening needs and conditions so you can make your own plant list2. A native plant is suggested just by entering your region, light requirement, soil moisture, leaf type, wildlife value target and bloom period.
This fall, the first plant to be removed is my non-flowering Chinese wisteria that I will probably replace with Audubon’s suggestion of a crossvine or trumpet vine. The second plant that I will take on will be the Big Leaf Periwinkle (Vinca major). About 1,000 square feet of my yard, beneath my hardwoods is covered with Big Leaf Periwinkle so I plan on using several plants to replace this ground cover in the part shady area with varying degrees of soil moisture. This will also increase the diversity of plants in my yard and year-round color interest. It is relatively easy to pull the Vinca major up by the roots, although they recommended mowing it first, because of the abundance of rain this year. Although I have already removed the Mimosa and Bradford Pear trees years ago, their former presence is evident by the frequent seedlings that still germinate in my yard, so this effort of eradication will require ongoing vigilance.
Planting of the alternative native plants will occur gradually over time as I source the plants from area nurseries, optimize my budget and observe the plants’ performance ornamentally and ecologically. I already have some of the native plants and I will encourage them to spread and may propagate them.
On August 5, 2018, the New Hope Audubon Society visited my yard after I filled out a simple online request form1. I heard about their Bird Friendly Habitat Certification Program2 after attending the Backyard Biodiversity talks which were presented at the Chatham Conservation Partnership meeting on July 19, 2018. My growing interest in the importance of my garden to wildlife came about because I began reading Doug Tallamy’s book, Bringing Nature Home3. The book was recommended at a Durham Garden Forum discussion this spring on native plants by Ken Moore, assistant director of NC Botanical Garden Emeritus.
Before The Visit
The certification level (silver, gold or platinum) is determined by calculating the percentage of your available property (about 13,250 sq.ft. in my case) covered by native or invasive plant species and the number of wildlife habitat options4 available in the yard. My 0.37 acre (16,117 sq. ft.) pie-shaped property benefits from a mature hardwood buffer area in the backyard so I thought I would achieve at least some degree of bird friendliness. The process is more efficient if you have a good plot survey of your property and a preliminary list of your plant species. I already had these items as a master gardener because we compiled these documents in our Landscape Management Plan as part of the Master Gardener Certification. I was also thankful that in previous years we removed invasive species such as the ice-damaged Bradford Pear (Pyrus calleryana) and a messy mimosa tree (Albizia julibrissin). There are multiple lists of invasive species to avoid planting in the Piedmont available at education institutional websites such as the North Carolina Botanical Garden5 and North Carolina State University Going Native website6as well as other organizations7,8.
During the Visit
Three representatives from the New Hope Audubon Society slowly walked around my yard and natural buffer area and patiently answered all my questions and took notes pointing out species of plants that were good, not so good and considered an invasive threat for birds. It was a customized assessment of my yard and garden with respect to native plant species and wildlife habitat and a very educational two hours. I was very delighted to be informed that I had the diminutive native Crane-fly orchids (Tipularia discolor) under my beech tree (Fagus grandifolia) which I had never noticed until they pointed them out as well as identified a shade-tolerant native Redring Milkweed (Asclepias variegata L.) near a very large white oak (Quercus alba). One of North Carolina’s smallest woody plants, Spotted Wintergreen (Chimaphila maculata, aka pipsissewa) was observed in the natural area. A native ground cover of Virginia snakeroot (Aristolochia serpentaria) was also scattered throughout the leaf litter. Other native shrubs of arrowwood (Viburnum dentatum) and St. Andrew’s-cross (Hypericum hypericoides (L.) Crantz) were quite common in my backyard, not to mention a young Black gumtree (Nyssa sylvatica).
As a gardener, I have been reformed through education. The New Hope Audubon Society pointed out the many invasive species and also the natives in my yard. Why are natives important? Native plants, especially native trees, host a variety of insects that are necessary for birds to feed their young and these plants host the insects that are vital to birds and the complex food webs that have evolved in our local area2,3. Lists of native plants ideal for your area can be found on these educational institution websites5,6 or you can use the helpful online tool9 by just entering your zip code into the Audubon Society database of over 700 bird-friendly North Carolina native plants10. I obtained a list of 116 native plants that are important bird resources, relatively easy to grow and available at area native nurseries for my area.
Native plants covered about 30% of my available property (14 native canopy trees, 10 understory trees, 11 native shrubs, 18 native herbaceous plants, 8 native vines as well as leaves and decaying ground matter). I would like to take credit for most of these plants but the truth is, the homebuilders left the natural area behind my house with the existing forest more or less intact. Nevertheless, I did plant several native herbaceous plants such as beauty berry (Callicarpa Americana) in my perennial borders, pollinator and rain gardens and native magnolias (Magnolia grandiflora) and red cedars (Juniperus virginiana) for privacy screens. I also had several wildlife habitat options such as a snag (part of a dead tree), leaves left as mulch, pollinator garden, bundles of branches, blue bird houses, bird baths and no cats.
I did some damage in the past and roughly 10 % of my available property contained what they referred to as high threat invasive plants. When I first moved to the United States, I was a dangerous gardener ecologically speaking. Armed with very little knowledge of the southeast ecology but a strong desire to plant attractive flowering trees and vines that I could not grow in Canada, I planted a golden rain tree (Koelreuteria paniculata)8, Chinese wisteria (Wisteria sinensis), a mimosa (Albizia julibrissin), burning bush (Euonymus alatus), Bigleaf periwinkle (Vinca major) and English ivy (Hedera helix). The Bradford Pear (Pyrus calleryana) planted by the homebuilders was not my fault. The Japanese honeysuckle (Lonicera japonica), Japanese stiltgrass (Microstegium viminium), heavenly bamboo (nandina) and purple beautyberry (Callicarpa dichotoma) invaded from elsewhere.
Native beautyberry (Callicarpa Americana) Photo taken by Wendy Diaz on August 9, 2018
After the Visit
The following week, I went to work pulling up some of the invasive species. I already was in the habit of pulling up mimosa seedlings as they germinated after a good rain; despite the removal of the mimosa tree over 3 years ago! Also on the clean up list were a small patch of Japanese stiltgrass, spiny olive, Chinese holly seedlings and the bigger job of removing tall nandina.
A few weeks after their visit, I received a package from the New Hope Audubon Society. In the end, my garden was certified a Gold Level wildlife habitat garden. They provided a plaque/sign that I hung proudly near our porch, a two page summary of their assessment listing number of native plant species in the canopy, understory, herbaceous and native vines along with recommendations for habitat improvement and provided a list of alternative plants to achieve the same landscaping goals only with native plants11. They also provided recommendations on the highest threat invasive species (10%) and other potentially invasive species. Am I going for a Platinum certification in the future? Yes, but that requires reducing the available property with high threat invasive species to less than 10% and increasing the coverage by natives from 30% to 50%! I will do the work in stages after I make a plan and that will be the subject of my next blog.
Ever since their visit, three things have happened to me 1) I am noticing invasive species everywhere and 2) I am more observant of the birds and caterpillars and enjoy taking their photographs and 3) I am more appreciative of the commonly ignored but important native species in my yard. Our HOA discourages fences so I have resolved to embrace the wildlife that use my yard as a transportation corridor and as for my much loved ornamentals like hostas and other deer-loving plants, they are restricted to zones near my house where the deer do not seem graze. I found this exercise educational and rewarding and I enjoyed getting the attractive sign and recognition for my gardening hobby and stewardship. I encourage like-minded gardeners to contact the Audubon Society for their own certification.
Few things scare me in the garden. Copperheads, brown recluse spiders and wasp nests come to mind. Now, poison ivy has climbed nearly to the top. Sure, you most likely won’t die from a poison ivy rash, but you may want to at a given point.
I had an encounter, unknowingly, with this vine and the rash is just abating after nearly three weeks. I have been on steroids and antibiotics and will end up with some scars. I did nothing after coming in contact with the poison ivy which made things much worse.
Recognizing Poison Ivy
So, we are going to pretend that this gardener surveyed her yard adequately for all poisonous vines before cutting in new beds. Let’s look at recognizing these plants and how to get them out of your yard. Keep in mind, in areas that you do not plan to garden, compost, or sit and enjoy the scenery, leave the plants alone. Nature has a purpose even for these devils.
As a review, poison ivy is a very prolific perennial vine/shrub with the distinctive three leaves. It can be found nearly everywhere in the landscape in both disturbed and undisturbed areas such as roadsides, hiking trails and wooded lots. This woody perennial spreads by runners and will grow in all types of soils. Also, there are many species of birds that eat the berries and pass them directly through their systems which get deposited in other areas to yet be eaten by different types of animals. They in turn redeposit the seeds in your garden. Interestingly, the animals who eat the seeds do not have an allergic reaction to the volatile oils. Lucky them! This process, together with the runners, greatly increases the likelihood that you will have a poisonous creeper of some kind in your yard.
Control with an Herbicide Containing Triclopyr
Armed with this information and knowing the result of an encounter with the plant, being proactive is the best measure. Every article I read online at 2:30 a.m. when the itching kept me from sleeping started out with “the easiest way to avoid contact is to be aware and get it out of your environment.” Not what I wanted to read at that point, but it’s the truth. The options for control really boil down to utilizing an herbicide containing triclopyr which is a woody brush killer. Yanking, pulling and digging are time consuming, risky, and ultimately not effective.
The herbicide should be applied directly to the leaves of the plant. Spray your target not the area. Spring and summer are excellent times to control poison ivy because the plants are actively growing so the herbicide will travel through the plant. Weather also plays a role. Temperatures should be in the range of 60-85 degrees F and avoid windy days. Check the label for dry times to make sure effectiveness is not lost during a rain shower.
Oftentimes, this is not a once-and-done project. You may need to spray again, but wait two weeks or more to give the first application time to work. Look for new growth when you are circling back and, for the best results, spray open leaves only. Be vigilant in your search as resprouting may occur several months later. Once the fall color appears on these plants, do not apply any more herbicide. Wait until spring when the leaves open up and the plants are growing.
Keep in mind that it may take more than one season to rid an area of poison ivy or oak. Check areas carefully and never be over confident. Remember our winged friends are spreading the berries!
Beware of Virginia Creeper Poison ivy or oak are not the only plants that can cause problems. A very small number of people, myself included, have reactions to Virginia Creeper. Although not as allergic as poison ivy, raphides, the sap of this vine can cause rashes and blisters if the skin is punctured.
Virginia Creeper is a popular native ground cover or climbing vine due in part to its beautiful fall color and blue-black berries. It is often planted by gardeners and spreads quickly once established. Most people are unaware of potential problems and don’t take precautions with a five-leaf plant as we do with the dreaded three leaves. If you have had a severe reaction to other poisonous plants, you would be well served to avoid Virginia Creeper. Follow the same steps previously outlined for poison ivy control if you wish to remove this plant from your environment.
Finally, here are some important reminders:
As with any treatment product, read the label carefully. Avoid the “this is good enough” method. Also, wear protective clothing.
Be very careful cutting down poison ivy plants as all parts of them are poisonous including a dead plant. Do not compost any parts of them; Carefully trash them.
Never burn any part of these plants. The smoke and ash can cause a rash and inhaling them can win you a painful trip to the emergency room.
I cannot warn you enough … do not be over confident!
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?
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.
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.
Tallamy, D.W. (2007). Bringing nature home: how you can sustain wildlife with native plants. Portland, OR: Timber Press.
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/
Leaflets three, let it be! Berries white? Take flight!
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.
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.
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 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.
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.