Holden Horticulturists Favorites

The Plants We Love – Again!

By Betsy Burrell, Holden volunteer

Once again we’ve asked The Holden Arboretum’s horticulturists to share some of their favorite perennials, shrubs and trees with our readers. While it’s unfair to expect them to have only a few favorites, they have chosen some very special plants that can grow here in Northeast Ohio and also be seen on Holden’s grounds.

 

Viki Ferreniea

It was difficult for Lead Horticulturist Viki Ferreniea to prune her original list of 13 plants down to four, but, when asked, she reluctantly narrowed it down to Camassia spp. (camas lily), Dryopteris erythrosora  ‘Brilliance’ (brilliance autumn fern), Polemonium reptans ‘Stairway to Heaven’ and Tricyrtus (toad lily).


With its profusion of beautiful blue star-like flowers, Ferreniea loves Camassia, a little known native bulb with several species and varieties. In late spring to early summer, strong 18-24” stems grow up through glaucous  -- the pale grey or bluish-green appearance of the surfaces of some plants -- strap-like leaves; the top third of these stems carry a mass of lovely blooms.  They do best in full sun and are tolerant of moist soil. For a striking effect, plant camas lilies in large groups among mid-sized perennials or low shrubs. Like the alliums and daffodils, Camassia disappears into a dormant state once flowering is finished.

 

The 14-18” tall evergreen fronds of Dryopteris erythrosora are perfection throughout the whole growing season and winter and have an attractive bronze sheen to them before maturing to a rich glossy green. This is accentuated by the coppery colored stems. Dryopteris performs best in shady spots with a humus-enriched soil that is moisture retentive; however, once well established it will tolerate periods of dry weather. They make an excellent companion for other shade loving plants such as Epimediums, Black Cohosh, Azaleas and bulbs.

 

Ferreniea’s next choice is ’Stairway to Heavan,’ a beautiful variegated selection of our native Jacob’s ladder. The rich emerald green leaves heavily margined in vivid cream with a touch of pink provides all season interest and color, and in mid to late spring produces intense blue flowers complementing the striking foliage. Polemonium grows 8-12” tall and performs best in high shade.

 

Tricyrtus is the perfect fall surprise for the shade garden. This engaging late summer-fall blooming perennial carries a myriad of orchid-like flowers in colors that range from pure white to purple-red and white speckled or spotted in deep red depending on the cultivar. The gracefully arching stems range from 12-24”.

 

Lori Gogolin

Holden Butterfly Garden horticulturist Lori Gogolin has submitted some lovely choices. One of her favorite shrubs is Abelia mosanensis (fragrant Abelia) because of its sweet fragrance and lasting pink flowers that bloom in late spring. This is a large, somewhat loose, semi-evergreen plant with glossy simple leaves, growing up to 6 feet tall. Abelia does well in sun to partial shade, preferring acidic, moist, well-drained soil. In autumn the foliage turns pretty shades of orange and red.

Gogolin chose Erythronium ‘Pagoda’ (trout lily) as one of her top spring bulbs. She loves its wide mottled leaves and yellow nodding flowers that bloom in April and early May. Pagoda is a strong grower, taller than other Erythroniums at 10” or so and easy to grow in partial shade, especially at the foot of trees and shrubs where the soil is rich and woodsy. 

 

The blooms of Helleborus hybridus (lenten rose) make it a welcome surprise in early spring. This clump-forming perennial features large, cup-shaped, rose-like, usually nodding flowers in various colors ranging from white to pink to light rose-purple. Lenten rose grows up to 18” tall in part shade to full shade, with little maintenance needed once established. 

 

Julia Viel

Julia Viel, the horticulturist at Lantern Court, recommends several beautiful flowering plants. She loves the magical appearance of the bright, vase-shaped, lilac-pink blooms of Colchicum ‘waterlily’ that rise without warning in autumn. In the spring, a clump of broad leaves emerges, stays awhile, and vanishes by midsummer. Her next choice is the superb hybrid bulb Allium ‘ambassador’ with its long growing season. Allium sends up foliage that dies back followed by 2 1/2-4 feet tall globular purple blooms from May and June continuing through July. Even after the bulbs are done blooming the flower stalks remain sturdy and add great shape and texture to a garden or flower arrangement.

 

For a fast growing groundcover that can fill in problem areas, Viel selected Epimedium versicolor, a part shade to full shade loving plant with delicate yellow flowers in the spring time. After blooming, compound red-mottled medium-green leaves with pointed, heart-shaped leaflets form on wiry stems. Another of Viel’s favorites is Peony ‘Paula Fay’, an early bloomer that has semi-double blossoms in vibrant hot pinks. Combined with the purple alliums, it makes for a great spring splash of color.  An ideal plant for cut flowers and bloom season,  Crocosmia 'George Davidson’ has bright yellowish-orange flowers on arching stalks among tall, green, sword-shaped foliage and can continue blooming for several months.

Lastly, Viel included Veronicastrum virginicum on her favorites list, an elegant plant that can reach 3-6’ high topped with clusters of creamy white flowers in candelabra-style spikes extending above dark green whorled leaves. This plant will provide a dramatic show when massed for effect or planted in a meadow garden.

 

Dawn Gerlica

Dawn Gerlica and fellow horticulturist Annie Rzepka work together in the Myrtle S. Holden Wildflower Garden. Because of Gerlica’s strong interest in ethnobotany, she has chosen some plants with intriguing stories behind them. These plants are not only pretty; they have historical uses and interesting relationships to humans and other species. She collects different varieties and cultivars of passion flower at home and most are tropical, but the native vine Passiflora incarnata, passion flower survives in Ohio. The flowers are built differently than most, with special structures that add to the beauty and make them strange little conversation starters. The original stories of how Passiflora were named and how people could see the different floral structures as representations of parts of the story of the crucifixion of Jesus Christ have always fascinated her.

For a favorite native shrub, she chose Vaccinium corymbosum (highbush blueberry). This plant is the main source for cultivars of blueberries that humans eat -- that in itself is enough reason to love them. They also feed birds, small mammals and other larger mammals. Gerlica also likes them for their interesting little white bell-like flowers that hang down in the spring. Sometimes the flowers buzz when the pollinators get momentarily trapped as they are entering or exiting. When planted in enough sunlight, the fall color is a very intense red.  “I have a personal attachment because my grandfather and I used to lay underneath the bushes wrapped tightly with netting to keep the birds out and we would eat all the berries we could reach, much to my grandmother’s annoyance,” she said.. “My mother bought me six cultivars for my 13th birthday, and I still have three of the original plants, many years later.”

 

The native tree Quercus prinus, chestnut oak has ridged corky bark and grows at a slow rate. This dark majestic tree is not as common as a red oak or a white oak; but because they grow so slowly, these huge trees are a lot older than most people think they are. The chestnut oak can be seen in some of Gerlica’s favorite spots: the less frequented areas of Little Mountain, the north slope of Stebbins overlooking the gulch, and the south edge of Upper Baldwin overlooking the Chagrin River.

 

Annie Rzepka

Rzepka likes the American native shrub Ilex verticillata 'Winter Red'. It is more profuse and vibrant compared to other cultivars, producing beautiful bright red fruit from early fall through winter.  Ilex verticillata is shade tolerant and does well in clay soil, wet soil, and requires little maintenance once established. It makes a lovely hedge and is also effective for erosion control or as an addition to a rain garden. More than 40 species of birds are known to eat the fruit including bluebirds, brown thrashers, cedar waxwings, flickers, gray catbirds, mockingbirds and robins. The dense branching also provides shelter, cover and nesting spots for birds.

 

For groundcover, the beautiful Tiarella cordifolia ‘Brandywine’ is one of her favorites. Introduced in the early 1990s from a nursery in the Brandywine River Valley, Tiarella is a vigorous grower with beautiful, glossy leaves that turn a lovely bronze in the fall and winter. The creamy white flowers, wispy and pixie-like, last for 6 to 8 weeks.  As a flowering perennial Rzepka’s pick is Rudbeckia hirta ‘Indian Summer’, a really showy Black-eyed Susan. It has extra-large, golden yellow flower heads and blooms from early summer until first frost. They will self-sow but need full sun and moist, well-drained soil. Rudbeckia looks wonderful in borders, gardens, meadows, or for naturalizing, and attracts butterflies. Another perennial favorite is Anemone hupehensis ‘Prince Henry’, also known as Japanese anemone or windflower. This anemone is medium sized to 18” and has beautiful 2” flowers in deep rose-pink with star-shaped petals. Annie likes the contrast of it against the dark foliage of Helleborus.

 

Another choice of Rzepka’s is Magnolia virginiana, commonly known as sweetbay magnolia. This small ornamental tree has great form, beautiful later-blooming flowers than most magnolias in the area, and the flowers smell fantastic. Sweetbays mature at about 20’ tall by 15’ wide, prefer full sun or partial shade, and are wet-site tolerant. The flowers open continuously from late May through June.

.

Toby Davidson

Display Garden horticulturist Toby Davidson’s top picks for 2012 include some great selections. He likes Lindera angustifolia, ornarrow-leaved spicebush, a large, multi-stemmed shrub growing from 10-15' tall. The 3-4" long leaves are green in the summer then turn a spectacular combination of yellow, orange and red in the fall. This shrub holds onto its leaves all winter (leaves are pale brown in winter) making it useful as a screen. The spicebush prefers full sun to part shade in moist but well-drained soil.

 

Another favorite is Lespedeza thunbergii 'Gilbralter'or Thunberg’s bushclover, a semi-woody plant that is easy to grow and easy to maintain. Bushclover needs full sun and soils on the dry side; the reward of growing this shrub is a 6' mass of rose-purple flowers that are so heavy they arch over, producing a fountain-like effect. The flowers appear in August. All of the stems are killed to the ground during our cold winters so cutting them back in March or April is needed.This leaves room for spring bulbs to grow around the base of this lovely lespedeza.

For a favorite tree, Davidson likes Acer griseum, commonly known as paperbark maple. There are three excellent examples of paperbark maple in the Display Garden, planted in 1981. They are now only about 25’ tall, but what he loves about them is the cinnamon-red thin papery bark of the trees. They look beautiful covered with snow in the winter. Plant one near the window you look out of during those cold winter months – just be sure it gets plenty of sun and good drainage.

 

We hope you’ve been inspired to explore Holden’s gardens and grounds to view these favorite picks -- or perhaps try your hand at growing them yourselves. For further resources be sure to visit the Corning Library where you’ll find a wealth of information on plants, including a lengthy series of Landscape Bulletins offering a wide range of information on gardening and landscape topics. For a copy of other favorites from our horticulturists, refer to “The Plants We Love” in the 2010 Summer Issue of Leaves.