Fraxinus mandshurica Rupr. Manchurian Ash. A native of northeast Asia, this uncommon, cold-hardy species is reported to attain nearly 100 feet in height in the wild. The trees being offered were grown from seed collected in the Russian Far East from several plants scattered in a population in which many were developing a good reddish purple fall color. The trees were approximately 30 feet tall and similar to green ash in form. The species has been rarely tested in this country, but it has potential for landscape use in our region and similar regions in the U.S.
Ames 26081 was collected as seed in September 1997 from several plants scattered in a population growing in a flood plain of the Ussyrisk River near Primorye, Russian Federation. The collection site was at latitude 43 deg. 47 min. 15 sec. North, longitude 133 deg. 49 min. 16 sec. East and an elevation of 609 meters. Associated vegetation included Chosenia arbutifolia, Ulmus japonica, Syringa, Euonymus alatus, Rosa, Paeonia lactiflora and Asparagus. The group that sponsored and participated in the collection trip that acquired this accession is known as the Midwestern Plant Collection Collaborative. In includes the Holden Arboretum , Missouri Botanic Garden , Minnesota Landscape Arboretum , Chicago Botanic Garden and the Morton Arboretum . These plants were donated by Harold Pellett and Nancy Rose of the Minnesota Landscape Arboretum. Probable hardiness USDA Zone 3.
Genista tinctoria L. Common Woadwaxen or Dyer’s Greenweed.
This small, hardy, legume family shrub is native to Europe and western Asia.
Its habit can be upright to ascending, with 10-year old plants reaching heights
of up to 3 feet with a spread of 5 to 6 feet. Slender stems stay green
even in winter giving the plants a twiggy appearance. In Europe it is
used as a
groundcover, specimen plant, or in the rock garden. It is a good plant
for poorer, drier sites with neutral soils. These plants may not perform
well on poorly drained soils. The small, up to one inch long leaves
are a rich bright green, but have no fall color. Flowers are bright
yellow, pealike and occur in early summer with sporadic flowers continuing
throughout the summer. The plants can be pruned back after flowering.
The literature reports no serious disease or insect pests. Little maintenance
is required save removing the occasional winterkilled stems.
Ames 25524 and A25525 were collected as seed by Mark Widrlechner of the USDA-ARS North Central Regional Plant Introduction Station and Robert Schutzki, Dept. of Horticulture, Michigan State University , East Lansing in September 1999.
Ames A25524 was collected in Okhtyrka, Ukraine. The habitat was a
flat open site in full sun on the edge of a road with an eastern exposure.
The plants were growing on well-drained sand. The latitude was: 50 deg.
15 min. 47 sec. North, longitude: 034 deg. 50 min. 43 sec. East, and the
elevation was 116 meters. Associated vegetation included grasses and
other
herbaceous plants.
Ames 25525 was collected northwest of Klishchevka, Ukraine, in the valley of the Ps’ol River. The habitat was open meadow/steppe in full sun. The site was fairly flat with sandy loam soil and good drainage. The latitude was: 49 deg. 16 min. 33 sec. North, longitude: 033 deg. 36 min. 19 sec. East, and the elevation was 80 meters. Associated vegetation included grasses, Tanacetum vulgare, Thymus, and Potentilla . Our expectations are that this accession will perform better at most trial sites because it was growing in a soil similar to those of prairie soils of the Midwest. Probable hardiness USDA Zone 3.
Hypericum androsaemum L. Tutsan. Native to western and southern Europe, west Asia and North Africa, and used frequently in cultivation as a border and specimen plant in Europe, this semi-evergreen shrub is found only rarely in the U.S. It is reported to make a vigorous, arching, spreading, bushy shrub of 2 to 3 feet high. The leaves are 3 ¼ to 4 inches long and 2 to 2 ¼ inches wide making them one of the largest-leaved, hardy Hypericums. Many leaves of the plants offered turned yellow in the autumn. The flowers are light yellow, ¾ inches in diameter, and occur 3 to 9 together in cymose clusters at the ends of lateral branches. The fruit is a berry-like capsule that changes from red to purple to black at maturity. Dirr reports that it appears to tolerate shady conditions.
Ames 2929 was acquired as seed from cultivated plants at the Arboretum Kostelec, University of Agriculture, Kostelec nad Cernymi Lesy, Czech Republic. These plants are not likely hardy through much of the NC-7 Trial area, and we recommend this accession especially to those cooperators in warmer locales. Probable hardiness USDA Zone 6.
Microbiota decussata Kom. Russian Arborvitae. A member of the Cupressaceae family, this shrub is native to southeastern Siberia where it forms shrublands with Pinus pumila in subalpine zones. It has many features in common with shrub forms of Thuja. Branchlets are arranged in flattened sprays that with soft, bright green needles appressed and scale-like. Branch tips nod or arch gracefully. Unlike Thuja, the foliage turns brownish purple in winter. If sited well, this plant makes a great groundcover with plants growing to about 1 ½ to 2 ½ feet high. Microbiota plants are reported to spread indefinitely. They prefer well-drained, moist, lighter soils, and some shade is tolerated and may be desirable in the heat that is typical of summers in much of North America. However, more than ½ a day in the shade is not recommended.
Ames 19148 was propagated from cuttings taken from four seedlings that germinated from a seed lot collected from cultivated plants at the Novy Dvur Arboretum, Czech Republic. Those plants were originally collected from the wild in Sichote Alin Mountains in the far east of the Russian Federation. Probable hardiness USDA Zone 3.
Quercus prinoides Willd. Dwarf Chinkapin Oak. Native from central Oklahoma and east Texas east to Alabama, New Jersey and north from Maine to southern Michigan, northern Illinois, southern Iowa, and southeastern Nebraska, this White-oak group plant is found in open upland woodlands, forest edges, and roadsides. In the northwest part of its range, it is often found on well drained, south-facing slopes and ridges in limestone-based soil, or near limestone outcrops. Dwarf chinkapin oak can form thickets of up to 7 feet tall and occasionally in the wild grows as small trees of up to 13 feet tall. Leaves are bright green and glabrous above, grayish tomentulose beneath. In autumn they can turn a rich dark red. Ovoid acorns often lack bitterness and are up to ½ an inch long and nearly ½ enclosed by the cup.
Ames 23752 was donated as seedlings by the Nebraska Statewide Arboretum . Original acorns were collected by Todd Morrissey, formerly with NSA, southwest of Salem, NE in the south ½ of Section 20 (T-1 N, R-15 E) of Richardson County. We did note last summer that leaves of some plants had mild cases of powdery mildew. Probable hardiness USDA Zone 4.
Rosa hybrids L. Hybrid roses 'Carefree Sunshine' and 'Radrazz'. Bill Radler, former director of Boerner Botanical Gardens , developed these two shrub rose cultivars. The NC-7 Trials were seen as a good vehicle for evaluating these plants through much of the Midwest and elsewhere. These roses were propagated on their own roots and donated by Radler and Conard-Pyle, Inc.
Ames 26192 'Carefree Sunshine' is described by Bill Radler as "a highly blackspot resistant, low growing, quick breaking, wide spreading, symmetrical mounded plant. The nearly single petalled flowers are a bright light yellow, they self-clean, are produced in small clusters, and exhibit a mild sweet fragrance. The leaves are light green and densely produced. The plants are tolerant of leafhopper and dependably crown hardy to -20F without winter protection."
Ames 26193 'Radrazz' is described by Radler as "a highly resistant, quick breaking, tightly compact, low growing, wide spreading, mounded plant. The semi-double flowers are bright cherry red which is most lovely at low light levels when the color absolutely glows. The flowers are produced in small clusters, they self-clean, and have a lovely sweet fragrance which while mild, does drift into the air. The leaflets are long, leathery, and dark green with a burgundy hue, and densely produced. The plants are tolerant of leafhopper, rose midge and Japanese beetles. Plants are dependably crown hardy to -20F without winter protection and are tolerant of late spring frosts." 'Radrazz' is trademarked under the name Knock Out®.
Salix pentandra L. Bay or Laurel Willow. Native to Europe and west Asia, the laurel willow has glossy, shimmering, deep green, and relatively broad leaves (2-5 inches long and 1 to 3 inches wide) making for a dense good-quality foliage canopy. While not free of insect and disease pests, the laurel willow is less troubled by these pests than many willows. While at our Station, the plants offered showed little or no signs of pest problems until late summer when the leaves developed mild leaf spot symptoms. Laurel willow can grow to 60 feet tall but usually much less with an oval compact form. Selected by the USDA NRCS Plant Materials Center of Aberdeen, Idaho , this clonal selection is referred to in NRCS literature as the Aberdeen Selection of Laurel Willow. The Aberdeen Selection is a medium to tall shrub with a dense round top, symmetrical crown and multiple trunks. It grows from 20 to 40 feet tall. It was selected for its “beauty, hardiness, and appropriate growth form for windbreaks.” Please see the enclosed Aberdeen PMC fact sheet. We believe this willow selection has potential for use in home and business landscapes.
PI 610668 was donated as stem cuttings by the Aberdeen, ID PMC. It was selected out of a collection of potential windbreak plants evaluated from 1981 through 1996. The Aberdeen PMC received the original plant material from the Rose Lake, Michigan PMC where it was collected from naturalized stands. Probable hardiness USDA Zone 3.
Spiraea flexuosa Fisch. Spirea. Native to northeast Asia, this species has a general distribution through eastern Siberia and the mountainous parts of north and central Mongolia. It is also found in parts of northern China, North Korea and western Siberia. In the wild the plants are found at forest edges and deciduous and pine mixed forest, forest meadows and sometimes subalpine meadows. This spirea is similar to S. chamaedryfolia, but lower and broader growing. It can grow up to 1.5 meters in height. Shoots are thin and flexuose. The narrow, 1 to 2 inches long, bright green leaves are oval-oblong to more lanceolate and serrate upward from the middle of the blade or higher. Last year’s fall color was variable from leaf to leaf and colors included purple, wine red, orange, yellow and green. Clusters of from 4 to 10 white flowers appear in May and June with fruit in late summer.
Ames 25357 is a population started from seed collected in northern Mongolia
at Omnodelger Sum, Henti Aimag in 1998 at latitude 48 deg. 09 min. 36 sec.
North, Longitude: 109 deg. 25 min. 14 sec. East. The elevation was 1524
meters, and the plants were growing on an 8% slope with a southern aspect.
Parent plants were growing in an open grassland dominated by Poa,
and forbs with scattered Larix trees at higher elevations. Soil
at the site was gravelly and formed from
eroded granitic rock. Fire had occurred at the site about two years
previous to the collection. Probable hardiness USDA Zone 3?
Ulmus hybrid ‘Patriot’. ‘Patriot’ Elm. ‘Patriot’ is the result of a 1980 controlled pollination by A. M. Townsend of the National Arboretum between Ulmus ‘Urban’ and a selection of the Chinese species, U. wilsoniana that was later released as ‘Prospector’. ‘Urban’ was selected from progeny of a controlled cross made in 1956 with the Netherlands selection N 148 (U. × hollandica ‘Vegeta’ × U. carpinifolia ) and U. pumila. ‘Patriot’ was selected for its pest and disease tolerance, wide, vase-shaped crown, fast growth, and high resistance to Dutch elm disease. It shows moderate resistance to the elm leaf beetle. This hybrid elm is reported to reach heights of over 40 feet with a crown spread of 25 feet in 13 years. ‘Patriot’ was released by the USDA-ARS in November 1993. It should be useful as a street, highway, home or park tree. A fact sheet of this cultivar can be found at the National Arboretum web page, http://www.ars-grin.gov/na/newintro/Patriot1.html .
PI 566597 was first received as budwood in 1993 from A. M. Townsend at
the U.S. National
Arboretum. Rooted cuttings were established during 1999 and 2000.
Probable hardiness USDA Zones 4 to 7.
Xanthoceras sorbifolium Bunge. Yellowhorn. This striking deciduous shrub or tree of up to 24 feet tall is native to northern China. It has a stout, upright habit. Lustrous green leaves hang on late into fall. The leaves are alternate, odd-pinnate, and composed of sessile, narrow, serrate leaflets. Beautiful stalked flowers occur in May and are about ¾ to 1 inch in diameter in racemes 6 to 10 inches long. The five petals of each flower are white with a blotch at the base that changes from yellow to red. To a degree, the flowers resemble popped popcorn, and another common name for this plant is the popcorn shrub. When in bloom, the plants are quite striking. Fruit is a 3-valved, thick-walled capsule that turns from green to brown. Seeds are pea-sized and dark brown. In the winter plants can be a bit coarse in appearance. This plant can be left as a shrub or pruned into multi-stemmed small trees. Plants at our Station are moderate in annual growth and have shown no signs of serious pest or disease problems. Yellowhorn can be difficult to transplant, and the plants do need good drainage.
Ames 26017 was obtained as bare-root seedlings from Lawyer Nursery, Inc. in spring 2000 and plants were grown on for another growing season. Seed was obtained from a northern Chinese source. Probable hardiness USDA Zones 4.
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Please send questions or comments to Mark Widrlechner at
nc7mw@ars-grin.gov