Callery Pear: Cut Them Down

Originally posted on May 1, 2019

This is such an important topic and such a huge problem that we thought it is worth sharing again.

Several years ago, I noticed something disturbing was happening to our prairie reconstruction.  Small little trees were popping up throughout the original prairie planting. I could not figure out where they were coming from, but they looked like pear tree saplings.  It wasn’t until I saw a large white blooming Callery pear tree in the spring that it all came together. 

Callery Pear

Although the flower clusters are beginning to fade, Callery pear’s white blooms are most obvious in the spring. We planted them for their explosion of spring blooms and nice fall color, but this ornamental tree has become highly invasive.  It threatens native wildlife habitat and has become a nuisance for private and public landowners.

This once favorite tree was planted extensively throughout the U.S.  The Callery pear – also referred to as Bradford pear – formed a nice pyramid to rounded shape.  The vertical limbs made it a nice median and street tree as well, ultimately reaching 30 to 40 feet tall and 20 -30 feet in spread.  This Chinese native was a harbinger of spring for decades with its prolific white blooms.  An added bonus was its reddish-purple fall color.

Despite all those positives, these trees have become problematic. This non-native, flowering tree was assumed to be sterile, but it is not.  It now cross-pollinates with other cultivars of Callery pear to produce hybrid offspring.  The fruit is ingested by wildlife and birds that spread the seeds across the countryside and into your yards.  It is aggressively displacing native vegetation, causing economic and environmental damage. 

Escaped Callery Pears*

The message to property owners is to remove the trees now while you can easily identify them in bloom.  We need to keep them from spreading to native areas.  It doesn’t hurt my feelings to see them go, because they are a weak-wooded, thorny mess. 

Native alternatives to Callery Pear:

  • Eastern Rudbud (Cercis canadensis)
  • Serviceberry (Amelanchier arborea or Amelanchier ‘Robin Hill’)
  • American Plum (Prunus americana)
  • Chokecherry (Prunus virginiana)
  • Blackhaw Viburnum (Viburnum prunifolium)
  • Rusty Blackhaw Viburnum (Viburnum rufidulum)
Blackhaw Viburnum in spring
Blackhaw Viburnum fruit and fall color

We have cut down the culprit, but still have a bunch more saplings to remove this summer. There was one more larger tree that was cut down near the Visitor Center. We will continue to eradicate these unwanted invaders in our prairies.  It will take time but I believe we can get the upper hand.  I would encourage you to remove them in your landscape as well and replace them with native trees. Callery pear has no place in the landscape anymore. 

*Image Source

Here is additional information on Callery pear trees from the Kansas Forest Service.

Plant Profile: American Beautyberry

This time of year, I look for those little surprises in the landscape that extend the season of beauty in the garden.  Asters in September and October and the native grasses in the late fall and winter punctuate the landscape with form, texture and color. One shrub that is a thrill for me to discover in the fall is American Beautyberry (Callicarpa americana). 

During the summer, American Beautyberry is nondescript and often overlooked. It has an open, loose appearance with medium green, opposite leaves.  Dense, lavender-pink flowers develop from the axils of the leaves in June. 

But the real show starts in August and continues through November, with fruit set so abundant that the stems are encircled with brilliant violet to magenta, round berries that are one quarter inch in diameter. These berry clusters appear along the stem, providing a spiraling whorl of color. Many birds including cardinals, mockingbirds, and robins adore the berries, which are stunning in fresh or dried arrangements.

American Beautyberry Photo Credit-Eric Hunt, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

This shrub thrives on neglect. It fruits more abundantly in full sun, but grows best in partial shade.  An area with morning sun and afternoon shade is the preferred location. Provide medium to moist soil close to paths and walkways so all who pass by can enjoy the berries.  This shrub would grow well as a colorful, informal backdrop to perennials, but looks best when used for naturalizing, or in mass plantings. 

Beautyberry Fruit. Photo courtesy of Katie Schmidt

American Beautyberry is native to much of the eastern and southern United States.  It is hardy to zone 6 so I treat it like a perennial, since it will die back to the ground each winter.  This will not affect the flowering. The plant will bloom and produce fruit on new growth each year. It matures to about three feet tall and two to three feet wide.  In warmer areas, it can reach eight feet tall and eight feet wide. 

We have offered this attractive native shrub at our plant sales, but most people don’t know what it is. As the name describes, it’s a native shrub with beautiful berries.  Find a place in your landscape for American beautyberry.

Attractive fruit even after an early cold snap. Photo courtesy of Katie Schmidt

Plant Profile: Possumhaw Holly, Deciduous Holly

If you have been walking through the Arboretum over the past few weeks, you probably noticed the deciduous holly.  Ilex decidua gets so much attention because of its incredibly lustrous fruit of red, orange, and yellow.  As the leaves fall away each year in November and December, the fruit magically appears and remains on the tree for most of the winter. 

‘Sundance’ Deciduous Holly

Fruit

These colorful berries are not a preferred food of birds, but become more appetizing when snow covers the ground.  Often trees are completely stripped of berries in a couple days after a heavy snow, because other food sources are not readily available.  Many birds, including cedar waxwings, flock to these trees to feed on the fruit later in winter.

Deciduous holly requires male and female plants to produce fruit.  Tiny white flowers appear before the leaves in March and April.  We have several male selections planted in close proximity to the female plants to assure the development of the attractive fruit each year.  It is best to keep the fruit producing female plants in the foreground and tuck the male forms out of sight.  We have used the branches with fruit cluster as holiday decorations.

Evergreen wreath
Holly berries as part of an evergreen wreath

Habit and Site Preferences

Deciduous holly, or Possumhaw as it is often called, is a small tree or large shrub that grows 15-20 feet tall. The smooth gray bark of the trunk and branches hold the fruit on the upper half of the plant.  Here in the Arboretum, we have both tree forms and suckering shrubs. Either is attractive and the suckering shrubs making a nice screen. As their name indicates, they are deciduous, dropping the leaves in autumn to fully reveal the berries.      

These deciduous trees grow best in full sun or partial shade.  Trees are more vigorous and produce more berries in full sun.  We have several along our creek channel and some around our parking lot.  They are quite adaptable to wet or drier conditions.

A few selections at the Arboretum:

‘Council Fire’ – An upright, rounded form growing 15′ tall and 10′ wide, this plant is superior for its ample fruit production and retention in clusters along the stems.

‘Council Fire’

Red Escort’ – This is a male selection (pollinator) with glossy leaves and a habit to 20′ tall.

‘Warren’s Red’ – This cultivar grows on the eastern border of the Arboretum parking lot.  It is very hardy and consistently produces fruit.  It is more shrub-like and upright, ultimately reaching 15’ tall. 

‘Warren’s Red’

‘Sundance’ – Nice tree form to 10’ tall and 8’ wide.  It has the longest lasting fruit, which is orange-red.

‘Sundance’

We are planning to have several deciduous holly varieties at our spring FloraKansas Native Plant Festival. Check out our Native Plant Guide for these cultivars along with Ilex verticillata varieties. Each will give you great winter color and habitat for the landscape. We love their hardiness and toughness as well as the beautiful fruit. Why not give them a try?

Plant Profile: The Versatile Viburnums

In addition to our interest in native trees, shrubs, wildflowers and grasses, one of the goals of the Arboretum is to grow plants which, while not native, are adapted to the rigors of the central Kansas climate. We are especially interested in displaying plants that are not widely grown in the area, but that show excellent hardiness and landscape potential.

The viburnums are a perfect example.  While not as widely known as forsythia and lilac, these shrubs deserve much more use in our landscapes. Not only do they offer year-around show of ornamental attributes, such as abundant floral displays, fragrance, outstanding fruiting characteristics, and fall color, they are also hardy and can serve a number of important uses in the landscape.

The Arboretum collection currently features a number of different viburnums, each displaying unique characteristics and qualities.  Most of the viburnums can be seen along the east border of the Arboretum, just south of the parking lot. A planting on the north bank of the Amphitheater features several additional kinds along with some newer varieties in the Pinetum.

Fragrant snowball viburnum – Viburnum x carlcephalum https://en.wikipedia.org/wiki/Viburnum_%C3%97_carlcephalum

The three most fragrant viburnums in the Arboretum’s collection are the Koreanspice Viburnum (Viburnum carlesii), fragrant viburnum (V. x carlcephalum), and Judd viburnum (V. x juddii). These three are somewhat similar in appearance because the latter two are hybrids involving a cross between the Koreanspice and another viburnum. They are medium size shrubs (6-10 feet tall). However, our collection also includes a dwarf form of the Koreanspice. All produce clusters of fragrant white flowers in April into May followed by inconspicuous black fruits.

Another fragrant type in the Arboretum is Burkwood Viburnum (Viburnum x burkwoodii). This semi-evergreen grows 8-10 feet fall and produces a white snowball-like flower cluster in April. The fragrance in somewhat sharper, almost spicy.

Like the burkwood viburnum, Willowwood viburnum (Viburnum x rhytidophylloides ‘Willowwood’) is semi-evergreen, retaining its furrowed, leathery leaves throughout much of the winter. This 7-10 foot shrub blooms in April and often to a lesser extent again in October. The blue-black fruits are attractive and can be quite abundant. Another form that is really attractive is ‘Alleghany’ which has tough, leathery leaves, attractive white flowers and abundant bunches of reddish-purple fruit.

Alleghany Viburnum. Photo by Emily Weaver

The Wayfaringtree viburnum (Viburnum lantana) grows as a large shrub or small tree (12-15 feet). While not fragrant to any degree, it produces an outstanding floral display in May, followed by red-black fruit in late summer that persists into fall. Fall color is often red, although it is not consistent.

Another large shrub is the Wentworth cultivar of the American cranberrybush (Viburnum trilobum ‘Wentworth’). The Wentworth viburnum was selected for its large, edible fruits, which progress in color from yellow to red to bright red and persist throughout winter. Birds seek out the fruits from fall through winter.  I have often thought that this shrub was at is best on bright winter days with the fruit highlighted against a snowy background. It is also attractive in May with its show of white, flat-topped flower clusters. A dwarf form of the American cranberrybush is found on the north bank of the Amphitheater.

Tucked up under the northeast corner of the Visitor Center is a viburnum that is very attractive. The Doublefile viburnum (Viburnum plicatum forma tomentosa ‘Shasta’) is stunning in bloom as the flowers are held horizontally above the branches.  It has insignificant fruit, but the spring flower show makes up for it.

Doublefile viburnum

The last two species in the Arboretum collection are the Blackhaw (Viburnum prunifolium) and southern or rusty blackhaw (V. rufidulum). These two species are native to Kansas and distinct from each other. Blackhaw viburnum is a large shrub or small tree that has smaller leaves and brighter fall color with oranges, yellows and reds. The dense flower clusters develop into purplish-black fruit that the birds love.

Rusty blackhaw is not widely available in the nursery trade at this time, but extremely adaptable and hardy. The glossy dark green leaves turn a nice burgundy-purple in the fall. Large, white, flat-topped clusters of flowers appear in early spring and later produce bunches of fruit that change from red to purple through the fall.  Again, many types of birds cherish the nutritious fruit.  These two native viburnums are my personal favorite, because they are the most adapted to our Kansas landscapes and have so many wonderful qualities.

Viburnum prunifolium. Photo by Janelle Flory Schrock

Viburnum rufidulum fruit. Photo by Emily Weaver

Any way you look at them, the viburnums are a versatile and highly ornamental group of plants that deserve a greater use in the landscape. We will continue to integrate new species and varieties into our plantings as development of the Arboretum progresses.






Plant Profile: Dwarf false indigo (Amorpha nana)

When we think of shrubs that grow in the prairie, lead plant (Amorpha canescens) is the first one that comes to my mind.  Rightfully so, the soft gray foliage and lavender flower spikes are a must for any summer prairie garden.  However, its lesser known cousin, dwarf false indigo (Amorpha nana) is blooming now in the Arboretum.  It makes you stop and take notice.

Dwarf false indigo can be found growing in the mixed-grass and shortgrass prairies throughout the Great Plains. In Kansas, I have seen it growing wild in Clark county.  It is not as widely distributed as lead plant, but I have found it to be quite adaptable.  It thrives in dry, open locations with plenty of sunlight.  Here in the Arboretum, it blooms in May but I have seen it bloom as late as mid-June.

The deep magenta flowers of dwarf false indigo have a sweet aroma like honey.  Each terminal flower cluster is covered in reddish-orange pollen that pollinators love to gather.  The flowers stand out against the bright green leaves.  This prairie shrub should not be pruned in the spring.  It blooms best from previous year’s growth.  A variety of pollinators flock to the fragrant blossoms, but the Silver Spotted Skipper butterfly use the soft leaves as a food source.  After the blooms, the small green seedpods develop, but turn dark brown later in the fall.

The name nana, meaning dwarf in Latin, refers to the shrub’s diminutive size, which ultimately reaches two feet tall.  While short, the deep tap root and finely textured leaves make it extremely drought tolerant.  Plant it en masse or along a border edge so you can enjoy the sweet fragrance of the flowers.  It prefers a well-drained soil, including clay and rocks.

Companion plants for this versatile shrub would be little bluestem (Schizachyrium scoparium), evening primrose (Oenothera macrocarpa), bottlebrush blazing star (Liatris mucornata), aromatic aster (Aster oblongifolius), shortstem spiderwort (tradescantia tharpii), narrowleaf coneflower (Echinacea angustifolia) and butterfly weed (Asclepias tuberosa).  This shrub deserves a place in your sunny prairie garden.

Join Us on Friday, May 12.

Dyck Arboretum of the Plains is offering a free wildflower to the first 25 families or individuals who obtain a new or renewed membership on Friday, May 12, for National Public Gardens Day!

We will also have FREE ADMISSION to the gardens for the day, and coffee and refreshments in the Visitor Center from 9-11 a.m.

THANK YOU TO EVERYONE WHO SUPPORTS THE DYCK ARBORETUM OF THE PLAINS!