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.