Native Mid-level Trees for a Bird-Friendly Garden

All the bird action is in the middle.

By Wendy Diaz EMGV

When we added two new bird feeders to our back yard last year during the COVID-19 lockdown, we enjoyed watching these frequent winged visitors and noticed that some birds waited their turn in a few nearby small trees and shrubs and these few plants were getting as much wildlife action as the bird feeders! 

Photographs by Wendy Diaz Birds Clockwise: Northern Flicker, Starlings, Mourning Doves, Red-bellied Woodpecker, Mourning Dove and Northern Cardinal, Brown-headed Nuthatch

We also noticed that the resident squirrel and some birds were taking a toll on the narrow branches of the closest mid-level Fringe tree (Chionanthus virginicus). I realized that after considering my backyard plants from a bird’s perspective, I had plenty of canopy trees and many near ground-level native perennials but lacked small trees and shrubs. This post will focus on native small trees that can potentially thrive in my backyard.  Native shrubs, along with the vertical element of vines, is a subject for a future blog post.

Squirrel bending branch of Fringe Tree and eating the drupes. Photo taken on May 25, 2021 by Wendy Diaz

Birds perched on Fringe Tree’s branches located near our bird feeder: Bluebird (May 30, 2021), American Goldfinch (April 27, 2019) and a Brown-headed Nuthatch (June 21, 2021). Photos taken by Wendy Diaz

Why Plant Mid-level Trees?

I have made a commitment to help native wildlife and especially birds by creating a good diverse habitat for them. After all, it is the least I can do considering there are nearly 3 billion less birds in North America than there was in 1970[1] due to threats such as habitat loss and degradation as well as cats and window collisions. Just like a garden landscape design benefits aesthetically from plants of varied height, so do birds. It is important for birds and for a diverse wildlife garden to layer tree heights and plants from the ground to the tree canopy and in between. Understory or small trees are used in the middle layer of the landscape and my backyard could do more for the birds and the environment if I planted more of these trees, both deciduous and coniferous (evergreen). 

Birds prefer trees of different heights both deciduous and evergreen for roosting and cover especially in winter. Above: Brown Thrasher on a low Magnolia branch above a small Redbud. Below: Red-winged Blackbird on Red Maple branch above the bird feeder. Photos taken by Wendy Diaz on June 4, 2021 and December 28, 2020, respectively.

Trees also need to range in size and density of leaf cover and I had limited cover for birds in my backyard landscape ever since I removed some small invasive trees, bushes and vines in addition to a Forsythia hedge.  The mid-level plain of my backyard vista, between 5 and 20 feet, is pretty bare and the recently planted replacement Fothergilla bushes are still small and slow growing.

My backyard has little small tree cover for birds especially in winter. Left photo: Bird’s-eye view of east-facing backyard in winter. Right photo: Horizontal view from the back deck. Photos taken by Wendy Diaz on February 20, 2021 and March 30, 2021, respectively.

A bird habitat should include food, water, cover and a place to raise their young. Plants are the foundation of the food web and a high value native wildlife habitat has a diversity of plants that flower and produce food throughout the seasons and cover in the winter too (evergreens) and native plants that are hosts for butterfly larvae that birds need to feed their young[2]. Tree cover is necessary to give birds a place to roost, interact socially, retreat from foul weather and escape from predators[3]

Along with providing a supplemental food like bird feeders it is also important to provide a water source (bird bath) and nesting sites (bird houses and snags) for cavity dwellers like nuthatches, woodpeckers and bluebirds. It is recommended that all bird feeders always be located within 10 feet of shrubby vegetation and especially evergreen plants[4] because this provides escape cover for small birds. In other areas of the backyard I have a brush pile and low-level perennials to provide quick escapes but not near the bird feeders. I needed more smaller trees and dense shrubs to provide nesting and escape cover along the edge our forested buffer. Native small trees can also provide additional ecological value besides protective cover by producing seeds, nuts, fruits for birds and other mammals, nectar for hummingbirds and butterflies and moths and providing hosts for caterpillars. To augment the native Fringe tree, I also wanted to plant more native small trees that would be well-adapted to our soil and climate.

Birds using man-made birdbath and birdhouses. Clockwise: Finch and Northern Cardinal, Carolina Wren and Finch, White-breasted Nuthatch, Eastern Bluebird, Northern Cardinal, House Finch and Tufted Titmouse. Photos taken by Wendy Diaz in 2021.

The Search for My Mid-level Tree Wish List

This spring I decided to research a list of potential native mid-level trees for my plant wish list this fall. Planting new trees is best done in the fall after the summer heat and when the soil is still warm and the new roots can grow. It makes them more resilient to survive the next hot summer. These young trees should be watered regularly during their first season until they are established.

Matt Jones, Chatham County Extension Agent recommended some bird-friendly native trees, especially for migrating birds, for the suburban yard during a virtual New Hope Audubon Society talk[5] in March. He suggested Eastern Red cedar (Juniperus virginiana), a common conifer in the Peidmont. It is dioceous and needs both male (for pollination) and female plants which produce fruits that songbirds like to eat. Full grown it is not exactly a small tree (40 feet) and prefers full sun. The cones and seeds attract cedar waxwings and robins and provides a nice place to hide due to its dense foliage. Another evergreen small tree which will provide cover in winter is the small but very fragrant flowers of Sweet Bay Magnolia (Magnolia virginianaand provides nesting sites. It grows to 15 to 20 feet tall and attracts kingbirds, robins and thrushes. He recommended Winterberry Holly (Ilex verticillata), a deciduous holly with gold fall leaf color that only grows to about 20 feet in height and would do best in the wet area of my yard. Also dioceous (need a male and female plants), it will provide winter interest in the landscape for its bright red drupes (fruit) which attract birds in the fall and persist into the winter. The Wax Myrtle or Bayberry (Myrica cerifera) is also a dioceous small evergreen tree or shrub and its fruit attracts chickadees, meadowlarks, titmouse, thrushes and Carolina wrens and can grow to heights of 20 feet. The birds eat small grey fruit in fall and are a large part of the tree swallow’s diet. He also recommended Black Cherry (Prunus serotina)Yaupon Holly (Ilex vomitoria) and of course the Fringe tree (Chionanthus virginicus) which has drupes (fruit) that attract robins, bluebirds, thrush, mockingbirds, catbirds and even the Scarlet Tanager and not to mention squirrels.

A quick search using the North Carolina Extension Gardener Plant Toolbox[6] with my site conditions criteria: Sunlight = partial shade (2-6 hours of direct sunlight per day), Soil texture = clay soil, Soil pH = Acid < 6, Soil Drainage = good but occasionally dry, Available Space to Plant = 6-12 feet (wanted only small trees),Attracts = Songbirds and Plant type = Native Plant, listed four small trees which I could plant that would meet my landscape design criteria. These small trees were Hawthorn (Crataegus Uniflora)Yaupon Holly (Ilex vomitoria), Blackhaw Viburnum (Viburnum prunifolium) and Arrowwood Viburnum (Viburnum dentatum). This was an ideal list because on a recent scouting of my untouched natural area revealed seedlings of Yaupon Holly, Blackhaw Viburnum and Arrowwood Viburnum. The small trees produce berries in the fall for songbirds and will add to the mid-level plain in my backyard landscape especially the arching shape of the Arrowwood and the pretty white spring blossoms of the Blackhaw Viburnum and the bright red berries of the Yaupon Holly in the winter. Arrowwood will be ideal to augment my new Fothergilla hedge behind one of the bird feeders because it is tolerant of both shade and full sun and good for grouping in masses along woodland edges and produces a deep burgundy[7]to copper brown fall color. If I see Hawthorn in a nursery I will be sure to purchase it so I can add to the environmental resilience of my landscape because it is heat tolerant and in Florida grows to a larger tree size. In other parts of the garden I already have a few yaupon hollies (Ilex vomitoria) and one weeping type (Ilex vomitoria ‘Pendula’) which is a very good small tree for a native landscape due to its architecturally pleasing form and dense branches (dense branches makes it more difficult for predators to access nests) and bright winter berries for the birds. 

Photos: Blackhaw Viburnum (Viburnum prunifolium)in bloom and closeup of bloom. Photo taken by Wendy Diaz on April 7, 2021 Arrowwood Viburnum (Viburnum dentatum) Photo taken by Wendy Diaz on October 7, 2021.

Some other small trees I have read about could also be great additions to my garden such as Witch hazel (Hamamelis virginiana), an autumn-blooming deciduous small tree with pale yellow flowers that grows 15 to 20 feet tall and birds eat the fruit in the fall but due to its drought intolerance I would have to plant it in a wetter portion of my backyard and not near the bird feeders. Swamp Bay (Persea palustris), a broadleaf evergreen small tree produces small blue drupes in the fall for birds. Serviceberry, Amelanchier also may be a good candidate for my yard as a deciduous small tree that grows to 15 feet tall and blooms as soon as the ground thaws from winter.

This spring I noticed a small seedling in the recently rehabilitated north side yard where I removed a bed of invasive Vinca major and subsequently planted native perennials. Perhaps I have a bird to thank for this Cherry Laurel (Prunus laurocerasusseedling which is an evergreen small tree that I can transplant for a hedge or use it for dense cover for birds in the winter near the bird feeder in my woodland garden. I recently identified a small tree of Possumhaw (Viburnum nudum) or Possumhaw holly (Ilex decidua) in the natural buffer area. It is a deciduous dioceous tree that grows 15 to 20 feet and produces red fruit that ripens in September that persists through winter and is eaten by songbirds. Hopefully, I will discover its seedlings in the future to transplant. Other small or mid-level trees that already grow in my yard are Redbud (Cercis candadensis)Dogwood (Cornus florida), Winged Sumac (Rhus glabra) and of course the Fringe Tree, (Chionanthus virginicus). 

Photographs of other small mid-level (understory) trees: Red bud, Dogwood, Fringe Tree and Winged Sumac. Photos taken by Wendy Diaz

Published plant lists that include small trees which may be ideal for your bird-friendly yard are as follows:

  1.  https://www.newhopeaudubon.org/wp-content/themes/nhas/library/docs/native-plant-growing-guide-piedmont-nc.pdf
  2. Table 1 Plant species native to North Carolina (including soil moisture and light requirements, region of primary occurrence and benefit to wildlife) in Landscaping for Wildlife with Native Plants
  3. Table 1 Important fruit-producing and seed-producing native plants in North Carolina and the timing of fruit or seed availability in Managing Backyards and Other Urban Habitats for Birds https://content.ces.ncsu.edu/managing-backyards-and-other-urban-habitats-for-birds
  4. Table 1 Some native host plants for North Carolina Butterflies in Butterflies in Your Backyard https://content.ces.ncsu.edu/butterflies-in-your-backyard

Where will I Find the Native small tree seedlings?

There are several ways to obtain native small trees to help birds in North Carolina and here is a list of resources:

  1. As I already mentioned, transplant seedlings from your own yard if you have a ‘natural area’.
  2. Collect seeds from trees growing wild in your area (not allowed in State Parks and Botanical Gardens).
  3. Attend a local Native plant rescue organized by the North Carolina Native Plant Society:

https://northcarolinanativeplantsociety.wildapricot.org/Sys/Login?ReturnUrl=%2fNative-Plant-Rescues

4. Buy from native plant nurseries:

Native Plant Nurseries

https://mellowmarshfarm.com/page/Bare-Root-and-Live-Stakes

  • or from the North Carolina Forest Service:

http://nc-forestry.stores.yahoo.net/

The Time to Plant Trees is Now!

With a list of 15 small native trees, I have plenty of small tree choices to plant this fall (or transplant) to fill in the voids in my garden landscape, support a more diverse wildlife habitat and to provide cover for birds around my bird feeders. In September, a hawk stayed about an hour in our backyard. Maybe watching for moles? It seemed happy with the bluebird house as a perch. Watching this high-level predator has given new urgency to my new landscape goal of planting more mid-level trees.

Cooper’s Hawk perched on bluebird house glancing at a Brown-headed nuthatch on the bird feeder.
Photographs taken moments a part on September 21, 2021 by Wendy Diaz.

References:


[1] https://www.3billionbirds.org/findings

[2] Easy Ways to Provide Wildlife Cover Triangle Gardener January-February 2018

[3] Landscaping for Wildlife with Native Plants NC State Extension:

https://content.ces.ncsu.edu/landscaping-for-wildlife-with-native-plants

[4] Managing Backyards and Other Urban Habitats for Birds 

https://content.ces.ncsu.edu/managing-backyards-and-other-urban-habitats-for-birds

[5] NHAS Monthly Meeting – March 4, 2021 Matt Jones, Tree Indentification-How birds use trees (especially during migration) and what trees would be good for our yards.”

[6] Plant Toolbox  https://plants.ces.ncsu.edu/find_a_plant/

[7] The American Woodland Garden, Capturing the Spirit of the Deciduous Forest. Text and photography by Rick Darke, Timber Press Copywright 2002.