20 May Some of our favorite “Oklahoma Proven” Trees and Shrubs
Oklahoma Proven is a plant promotion program coordinated by faculty in the Department of Horticulture and Landscape Architecture at Oklahoma State University. The goal of the program is to recommend plants well-adapted for use across Oklahoma.
With that said, we have found that most of our clients are as particular as we are regarding plant selection. The last thing we want to do is encourage our clients to have a “Me Too” landscape, in other words, no more cookie cutter keep-up-with-the-Jones landscapes. Over the past 3 decades, as we have grown a presence in the Oklahoma market, we have seen the over-use of so many trees and shrubs i.e. Bradford Pear, Blue Atlas Cedar, Pin Oak, Burford Holly and Manhattan Euonymus to name a few. Even though these plants have many pros and some cons, the overuse of them has removed the uniqueness of their positive attributes. So as we go over “Some of our favorite” Oklahoma Proven varieties, it is keeping with the theme of creating a unique atmosphere in your landscape. I have heard from clients who love to have a knock at the door with a passerby asking, “what is that tree?” or “what kind of shrub is that”?
Rhus typhina ‘Bailtiger’ Tiger Eyes® and ‘Laciniata’ Sumacs are native to Oklahoma and these selections have unique characteristics. Tiger Eyes® is bright lime green to yellow all summer, turning brilliant bronzy red in fall. Tiger Eyes® can grow 6 to 7 feet tall. Laciniata or laceleaf sumac has deeply divided leaflets that create a fine textured, lacy appearance and turn shades of red, orange and yellow in fall. This cultivar can grow 10 to 15 feet tall. As with any other sumac they spread by suckers forming thickets. Fruit form in pyramidal clusters and are hairy red berry-like drupes that persist into winter providing interest and food for wildlife. Flowers that bloom in spring attracts bees and butterflies. These selections of sumac are all great for naturalized areas and erosion control. •Exposure: Full sun to part shade •Soil: Prefers moist, well-drained soil; tolerant of high pH soils and pollution •Hardiness: USDA Zone 3-7
Juniperus virginiana ‘Taylor’ J. chinensis ‘Saybrook Gold’ J. horizontalis ‘Monber’ Icee Blue® This collection represents the very diverse genus Juniperus, which has several species and many cultivars within each species. Junipers come in upright, spreading or low groundcover forms. ‘Taylor’ is a narrow, upright cultivar that grows about 4 to 5 feet wide-reaching 15 to 20 feet tall and is excellent for tight spaces. ‘Saybrook Gold’ is the brightest gold, holding its color year round with a compact, spreading habit to about 30 inches tall and 6 feet wide. And Icee Blue® is a low, mat-forming species with beautiful silver-blue foliage. In general, junipers are adapted to a wide range of soils and withstand hot dry conditions once established. •Exposure: Sun to part shade •Soil: Moist, well-drained •Hardiness: USDA Zone 4-9
Euonymus bungeanus, Winterberry euonymus is a large shrub to small tree with pendulous branches and light green foliage. Flowers are yellowish-green but not showy. Fruits are pinkish capsules that split open at maturity revealing an orange aril (fleshy seed covering). Fall color can be yellow to orange and red. The bark is green with a rough texture and is also quite attractive. Winterberry grows 15’-24’ high and just about as wide. It is very adaptable and quite drought tolerant. It is mostly resistant to scale insects that are common on other euonymus species. Winterberry makes a great patio or specimen tree. •Exposure: Full sun to part shade •Soil: Tolerates a wide range of soils •Hardiness: USDA Zone 4-7
Chilopsis linearis, Desert-willow cultivars Desert-willow is not a willow at all, and prefers dry, well-drained soils, compared to true willows, which grow along streams and ponds; in fact, it will not tolerate heavy, wet soils. Because it likes the hotter, drier climates it is an excellent choice for western Oklahoma. Desert-willow grows as a small tree 15’-30’ high and 10’ to 25’ wide. It is a loose, gangly tree favored for its colorful, funnel-shaped flowers that put on their biggest show in early summer, and then bloom sporadically throughout the rest of summer. Flowers can be white, pink, rose, or lavender with purple markings inside and are sweetly fragrant. Foliage is a rich green in summer with no fall color, falling early to reveal the interesting branching structure. Several cultivars exist. Desert-willow makes a great patio or small specimen tree and attracts hummingbirds and other birds. Exposure: Full sun •Soil: Dry, well-drained soils •Hardiness: USDA Zone 7-9
Viburnum dentatum ‘Christom’ Blue Muffin® Blue Muffin viburnum is a small, compact version of the native arrowwood viburnum growing about 3’ to 5’ high and just as wide. Blue Muffin prefers moist, well-drained soils, but is adaptable to a wide range of other soils. Established plants are somewhat drought tolerant, have no serious pest problems, and require very little maintenance making them excellent for the urban landscape. As with many viburnums, Blue Muffin offers season-long interest with white spring flowers, dark green summer foliage that turns red and orange in fall, and blue fruits the birds love in late summer/fall. Prune right after flowering, but only if necessary. Grow Blue Muffin as a specimen, in groupings, in shrub borders, as a foundation planting or as a hedge. Exposure: Sun to part shade Soil: Moist, well-drained Hardiness: USDA Zone 3-8.
Vitex spp., Chaste Tree Vitex is a multi-stemmed large shrub but can be trained into a small tree. Leaves are palmately compound and dark green. Flowers appear in early summer and continue to bloom sporadically through summer and fall. Flowers of Vitex can be blue, lavender, pink or white. Old strains had small spikes of flowers; improved varieties have large spikes (8” to 12” long) of colorful flowers that are fragrant and make excellent cut flowers. Vitex is not too picky about soil and is easy to grow, very heat, drought and pest tolerant and an excellent choice for a xeric garden. Vitex is often considered an excellent replacement for lilacs, which grow much better in colder climates, and it attracts butterflies and hummingbirds. •Exposure: Sun to part shade •Soil: Moist, well-drained •Hardiness: USDA Zone 4-9
Abelia x Grandiflora ‘Kaleidoscope’, ‘Little Richard’, and ‘Rose Creek’ Several new, compact forms of glossy abelia are becoming very popular. ‘Kaleidoscope’ grows 2-3’ high and slightly wider. In spring leaves appear on bright red stems with lime green centers and bright yellow edges, but variegation does not scorch or burn in hot weather, and in fall color deepens to shades of orange and fiery red. Soft pink flower buds open to white in late spring. ‘Little Richard’ is 3’x3’, evergreen, with vivid green leaves in summer, taking on a tangerine-pink color in fall; white flowers bloom from summer to the first frost. ‘Rose Creek’ grows 2-3’ high and 3-4’ wide; is evergreen, with crimson stems. New leaves have a pinkish cast, maturing to lustrous dark green, and turn purple in cold weather. Small white flowers are surrounded by persistent rosy pink sepals. Use these abelias in containers, as formal or informal hedges, accent plants, in mass plantings, or in foundation plantings under windows. Abelias also attract hummingbirds and butterflies to the garden. •Exposure: Sun to part shade •Soil: Moist, well-drained, acidic •Hardiness: USDA Zone 6-9, evergreen in 7.