Water conservation in a landscape is an important issue because periodic water shortages are common in many regions of the world. This increases the importance of specifying landscape plants that require less water and matching the plant to site microclimates. Our objectives were to establish water-use rates for three herbaceous landscape plants and to determine the level of water reduction these plants can tolerate while maintaining both visual and landscape quality. Water use rates were determined for Schizachyrium scoparium (Little bluestem), Hosta spp. (Hosta) and Festuca cinerea `Dwarf' (Dwarf blue fescue) in studies using pot lysimeters at the Univ. of Nebraska Horticulture Research Greenhouse facility. Each lysimeter was watered to saturation, allowed to drain to field capacity, and weighed. The lysimeters were weighed again 24 h later, and the process was repeated to determine daily evapotranspiration. Results indicated that hosta used less water than dwarf blue fescue and little bluestem. In a subsequent study to compare the relative effects of withholding irrigation among these species, seven groups of five replicates of each species were grown in 1 peat: 0.33 vermiculite: 0.66 soil: 1 sand (by volume) in 7.6-L containers. Each container was watered to saturation, allowed to drain for 24 h to reach field capacity, and allowed to dry down in 10-day increments. Results of the dry-down study indicated that little bluestem maintained the best visual quality for the longest duration of drought, followed by dwarf blue fescue and hosta in decreasing order of visual quality.
Catherine A. Paul, Greg L. Davis, Garald L. Horst, and Steven N. Rodie
J.G. Norcini and J.H. Aldrich
Eight species of low-growing woody and herbaceous landscape plants were evaluated for tolerance to 1.1 or 2.2 kg a.i. bentazon/ha (plus a crop oil) applied over the top twice 7 days apart. Raphiolepis indica L. Lindl. `Alba' was the only species tolerant to bentazon in either of two experiments. Bentazon injury to Liriope muscari (Decne.) L.H. Bailey `Evergreen Giant' was minor (slight chlorosis) and would probably be tolerable under most landscape situations. Injury (primarily chlorosis/necrosis) to Carissa macrocarpa `Emerald Blanket', Juniperus horizontalis Moench `Bar Harbor', Pittosporum tobira (Thunb.) Ait. `Compacta Green', Trachelospermum asiaticum (Sie-bold & Zucc.) Nakai `Aslo', Ophiopogon japonicus (Thunb.) Ker-Gawl., and Hemerocallis × `Aztec Gold' was significant and therefore unacceptable. Chemical name used: 3-isopropyl-1H-2,1,3-benzothiadiazin-(4)-3H-one 2,2-dioxide (bentazon).
Michael S. Dosmann
Aconitum sinomontanum is a robust perennial monkshood native to China that shows promise as a cultivated ornamental. However, nothing has been reported about the germination requirements of the species, and little is known about the requirements of the genus as a whole. The objective of this study was to test the influence of stratification (moist prechilling) on germination of A. sinomontanum seeds. The seeds were from wild-collected plants of identical provenance growing at the Arnold Arboretum (Jamaica Plain, Mass.). After harvest and before stratification, seeds were stored dry at 38 °F (3.3 °C) and percentage germination was assessed after seeds were stratified, also at 38 °F, for 0, 21, 42, or 84 days. It is likely that stratification is required for seeds of this species to germinate, as unstratified seeds failed to germinate through the duration of the experiment (73 days). The highest level of germination (90.8%) was achieved after 84 days of stratification, and as length of stratification increased, so did percentage germination and indices of peak value and germination value. Days to maximum germination decreased with additional days of chilling. Growers wishing to germinate seed of this species should stratify seed for 3 months to achieve the highest level of germination.
Holly L. Scoggins
functions ( Lewis and Affolter, 1999 ). Gardens are critical tools for teaching identification, use, and care of woody and herbaceous landscape plants. The value of this function cannot be understated. A recent national survey created a list of competencies
Dewayne L. Ingram, Charles R. Hall, and Joshua Knight
has summarized the life-cycle impact of landscape plants on GWP. Herbaceous plant materials have minimal impact on GWP in the landscape; however, they contribute to environmental quality in other ways. Woody and herbaceous landscape plants provide many
Shasha Wu, Youping Sun, and Genhua Niu
landscape plants has been determined by Niu group since 2006 ( Niu and Rodriguez, 2006a , 2006b ; Niu et al., 2007 , 2010 , 2012a , 2012b ). Considering the huge number of plant species potentially available for landscapes, there are still thousands of