Eighty horticultural wildflower taxa were evaluated for performance at three locations over three years in Georgia (USDA climatic zones 7-9). Plant performance and persistence were rated as superior perennial/reseeding annual, secondary perennial, annual, and unadapted. Length of bloom season for each species was determined at each location. Forty-eight species were rated as superior, 11 as secondary, 14 annual, and seven were not adapted. From these data, specialty mixes for meadow gardens, roadside beautification, landscape color, and native plant restoration areas have been formulated for use in cost-efficient landscape plantings. The mixes contain 10-15 species with overlapping bloom seasons to provide color during most of the growing season of eight months.
W. L. Corley and A. E. Smith Jr.
Dale T. Lindgren
Penstemon, a U.S. native plant/wildflower, is increasing in use as a landscape plant. Penstemon species are commonly propagated by seeds. However, species vary greatly in percent seed germination,
Seeds from eight sources of Penstemon germplasm were given cold moist stratification periods of either 0, 2, 4, 6, 8 or 10 weeks. One-half of the seed for each treatment was scarified with sandpaper. The study was repeated twice, once in 1989 and once in 1990.
Seed germination varied with species, and with the length of stratification. Greatest germination occurred at the 6, 8 and 10 week periods and the lowest germination occurred with no stratification. There were also differences between species in percent germination, Average percent germination was highest for P. gracilis and lowest for P. haydenii There was a significant species × stratification interaction, Seed scarification did not influence germination as much as seed stratification in these studies
Kerrie B. Badertscher
A 5-acre neighborhood park in Longmont, Colo., was designed for a senior design class. A series of town meetings coordinated with special interest groups was used to develop the design. The first goal of the town meetings was to provide the community with a sense of ownership of the park. Park requirements included a protected wetland, recreational needs, and circulation to other parks and open space. The design integrated facilities placement, recreational equipment, bird viewing areas, a wetland interpretive walk, and ease of maintenance and accessibility. Input from the town meetings led to several design manipulations. Native vegetation was reclaimed with native forbs and grasses. The use of native plantings integrated into the design will be reviewed as will the input from the several groups. This will focus on the educational process and impact on the final document without a loss of integrity of the design.
James M. Affolter and Marta Lagrotteria
The province of Cordoba in central Argentina is naturally rich in aromatic and medicinal herbs that are in high demand as ingredients in teas and herbal medicines. Most of the herbs sold are harvested from natural populations, and this activity is a primary source of income for families in the Sierra de Cordoba region. As a result of over-collection and other poor harvesting practices, many native plant populations have been reduced in size or extirpated. The economic consequence of the gradual decline of this resource has been a loss of real income in rural areas coupled with a pattern of emigration from small towns to larger cities. PRODEMA is a collaborative effort by universities in Argentina and the United States, with the sponsorship of the Cordoba government, to domesticate and to market the most commercially important species. Horticultural research has focused on the development of propagation techniques and identification and selection of desirable chemotypes.
L.L. Lockett, C.B. McKenney, and D.L. Auld
Many segments of private industry use data gathered from public attitude and opinion research as an integral part of the planning, program development, and evaluation process. These basic techniques were used to determine public perception of five species of Texas native plants grown at three irrigation rates under xeriscape conditions. Nearly half of the average annual residential water costs go to lawns and gardens. Minimizing the amount of water used in irrigation could provide significant savings of money and a precious natural resource. The complexities of measuring social attitudes, how to develop a valid survey instrument, methods of analyzing survey data, and appropriate interpretation will be discussed. Use of public perception could be a powerful tool in developing water conserving technologies.
Lyn A. Gettys and Michael A. Schnelle
plants. It is becoming increasingly clear that some native plants have the ability to grow aggressively, outcompete other native species, and form dense monocultures, resulting in the same problems associated with invasions by introduced plants. The
David L. Creech
The SFA Arboretum is evidence that small horticulture programs can capitalize on what's right outside the back door of the building. Initiated in 1985 as a lab project in a landscape plant materials course on the south side of the Agriculture building, the collection has grown to over 3000 taxa displayed in a ten-acre public garden setting. The Arboretum's mission is to 1) promote the conservation and use of native plants, 2) evaluate “new” landscape plant materials, and 3) serve as a living laboratory for students in Horticulture, Agriculture, Biology and Forestry. Funding improvements in the last two years and the creation of a Board of Advisors and a Volunteer Corps organization has addressed problems in routine landscape maintenance and getting “new” garden developments off the ground. A “Plants with Promise” program acquires, tests, propagates, distributes and promotes superior “new” woody plants. Outstanding performers include Bignonia capreolata 'atrosangainea', Campsis grandiflora, Cinnamomum chekingensis, Euschapis japonica, Scuttelaria suffretescens 'pink', Sinojackia rehderiana, Taxodium mucronatum, Viburnum propinquum, various Styrax species and varieties, several Michelia species, Illicium henryi, three Mexico oaks, and many others. AutoCAD maps and a plant inventory database tracks plant location and acquisition data. A just-completed GIS-based analysis of the university forest paves the way for a campus-as-arboretum effort. The premise of this paper is that high-visibility, easy-access display/evaluation gardens offer Horticulture Departments the opportunity for enhanced student recruitment, community involvement, external funding, environmental education, and the potential for significant contributions to the nursery industry.
Lyn A. Gettys and Kimberly A. Moore
Wetland restoration is an important way to improve ecosystem services, but many wetland nurseries lack the facilities that are traditionally used to produce large numbers of native plants used in these projects. Our goal was to evaluate growth and performance of four wetland species in a variety of substrates, fertilizer regimes, and irrigation methods under greenhouse conditions. Plants were grown in pots with drainage holes filled with one of four substrates (potting substrate, topsoil, sand, 50/50 mix of topsoil, and sand) amended with 0, 1, 2, or 4 g of 15N–3.9P–10K controlled-release fertilizer per liter of substrate. Irrigation was supplied via an overhead system or subirrigation. After 16 weeks of production, plants were scored for visual quality and plant height before a destructive harvest. Broadleaf sagittaria (Sagittaria latifolia) was mostly unaffected by substrate type but performed best when subirrigated and fertilized with 4 g·L−1 of fertilizer. Growth of skyflower (Hydrolea corymbosa) and cardinal flower (Lobelia cardinalis) was best when fertilized with 2 or 4 g·L−1 of fertilizer and grown using overhead irrigation. String lily (Crinum americanum) was unaffected by substrate type but produced the largest plants when subirrigated. These experiments provide guidance for cultivating these wetland species under greenhouse conditions, which may allow growers to efficiently produce plant material needed for the restoration market.
Stephen L. Love, Asunta Thompson-Johns, and Timothy P. Baker
Eight hundred and fifty-three clones of Russet Burbank and 1012 clones of Lemhi Russet were obtained from Native Plants, Inc. in 1988. The clones were produced via a tissue culture system designed to produce somoclonal variants. Four cycles of selection were completed from 1988-1991. Selection was based on resistance to blackspot bruise, a tuber flesh discoloration caused by condensation of free tyrosine; or the ability to produce light french fry color following cold storage. At the end of the four selection cycles all but six Russet Burbank clones and seven Lemhi Russet clones were eliminated. ANOVA across years was completed for the eleven somaclonal variants and Russet Burbank and Lemhi Russet checks.
Of the Russet Burbank clones, three were significantly (p = .05) more resistant to blackspot bruise and one had significantly better fry color after cold storage. All four clones had significantly reduced yield in comparison to the check clones. Of the Lemhi Russet clones, three were significantly more resistant to blackspot bruise, and four had significantly better fry color than the check clone. Only one of the seven clones (one with superior fry color designated L1908) did not show a significantly lower yield potential.
Christopher C. Dickinson, Alexandra J. Weisberg, and John G. Jelesko
Poison ivy [Toxicodendron radicans (L.) Kuntz] is a widely recognized native plant species because of its production of urushiol, which is responsible for delayed contact dermatitis symptoms in humans. Poison ivy is predicted to become both more prevalent and more noxious in response to projected patterns of climate change. Future studies on poison ivy chemical ecology will require reverse genetics to investigate urushiol metabolism. A prerequisite for reverse genetic procedures is the introduction and expression of recombinant DNA into poison ivy tissues. Poison ivy leaves and cotyledons were marginally susceptible to vacuum- and syringe-agroinfiltration and expression of two firefly luciferase (LUC)–based reporter genes. The efficacy of agroinfiltration and transient LUC expression was dependent on leaf age and plant growth environmental conditions, with young leaves grown in magenta boxes showing highest transient LUC expression levels. Agroinfiltrated leaves showed an Agrobacterium-dependent accumulation of brown–colored pigments. Biolistic transformation of a LUC reporter gene did not show brown pigment accumulation and readily displayed transient LUC bioluminescence in both leaves and cotyledon tissues. These studies establish best practices for introducing and transiently expressing recombinant DNA into poison ivy leaf and cotyledon tissues, on which future reverse genetic procedures can be developed.