landscaping have been found to be invasive, and sales of these plants have declined dramatically in recent years ( McCoy 2011 ). Two such invasive shrubs are japanese barberry and winged euonymus. Ironically, some of the same traits that brought japanese
Pragati Shrestha and Jessica D. Lubell
Melissa Bravo, Antonio DiTommaso, and David Hayes
native virginia creeper are widespread ( Table 2 ) in the natural resource areas with introductions dating from 1900 to 1910 ( Table 1 ). Burning bush, japanese barberry, morrow’s honeysuckle, tatarian honeysuckle, sweet mock orange ( Philadelphus
James A. Gagliardi and Mark H. Brand
or more of the respondents reported working with norway maple, japanese barberry, and winged euonymus at their place of employment, although all three species are categorized as invasive on Connecticut's Invasive Plant List (Connecticut Invasive
Diana L. Berchielli-Robertson, Charles H. Gilliam, and Donna C. Fare
A 2-year study evaluated the effects of three weed species: eclipta [Eclipta alba (L.) Hasskarl], prostrate spurge (Euphorbia supina Raf.), and wood sorrel (Oxalis stricta L.) on growth of container-grown `Gumpo White Sport' azalea (Rhododendron eriocarpum), R. x `Fashion', and Berberis thunbergii DC. var. atropurpurea `Crimson Pigmy'. Competitiveness among weed species as ranked from greatest to least was eclipta, prostrate spurge, and wood sorrel. Greater populations of eclipta and prostrate spurge resulted in decreased shoot dry weight of `Fashion' and `Gumpo White Sport' azalea. Prostrate spurge had a similar effect on `Crimson Pigmy' barberry in both small (3.8-liter) and large (15.2-liter) containers, while eclipta reduced shoot dry weight of barberry only in large containers. Wood sorrel had little effect on shoot dry weight of `Fashion' and `Gumpo White Sport' azalea.
Christine E. Harris, Eric Simonne, Peggy Codreanu, and Joseph Eakes
Feeding damage by white-tailed deer to vegetable and ornamental crops are often adverse to plant growth, and result in economic and aesthetic losses. While the efficacy of commercially available deer repellent products is questionable, plant extracts may provide an environmentally sound alternative to traditional chemical treatments. Commercially available plant extracts (Dusty Miller, peppermint, Madagascar periwinkle, wax myrtle, barberry, juniper, geranium, rosemary, lemon balm, and yucca) known to be unpalatable plants were chosen as treatments. Thiram and putrescent egg spray were used as positive controls along with a no-spray treatment. Gomphrena were grown off-site in trade gallon pots and used as test plants. Sixteen deer were confined in two 1-acre study pens at the Auburn Univ. Deer Research Facility. Feeding damage was recorded daily using a 0 to 3 rating scale corresponding to 1/3, 2/3, and complete destruction, respectively. All damage data were converted into percent damage. Barberry and wax myrtle extracts made gomphrena more palatable to the deer as feeding damage exceeded that of the untreated plants. However, lemon balm, rosemary, yucca, and peppermint provide some level of protection against feeding damage to gomphrena. Fifth-day damage ratings for these extracts were 37%, 35%, 13%, and 19%, respectively. Fifth-day damage for untreated plants was 40%. Peppermint and yucca extracts appear to be promising alternatives to thiram and putrescent egg-based products.
W. Jack Rowe II, Daniel A. Potter, and Robert E. McNiel
Twenty-six purple- or green-leaved cultivars representing 12 species of woody landscape plants were evaluated in the field for defoliation by Japanese beetles (Popillia japonica Newman) over three growing seasons. We further evaluated the hypothesis that, within closely-related plants, purple cultivars generally are preferred over green ones by comparing beetles' consumption of foliage in laboratory choice tests and their orientation to painted silk tree models baited with Japanese beetle lures. Cultivars of Prunus cerasifera Ehrh. and hybrids of that species [e.g., Prunus ×cistena (Hansen) Koehne, Prunus ×blireiana André] were more heavily damaged than nearly all other plants tested. Among maples, Acer palmatum Thunb. `Bloodgood' and A. platanoides L. `Deborah' and `Fairview' were especially susceptible. None of the cultivars of Berberis thunbergii DC, Cercis canadensis L., Cotinus coggygria Scop., or Fagus sylvatica L. were heavily damaged, regardless of foliage color. In the choice tests, purple Norway maples were preferred over green ones in three of four comparisons, but preference varied within the other plant genera. In fact, more beetles oriented to green-leaved tree models than to purple ones. Our results indicate that within a genus, purple-leaved plants do not necessarily sustain more damage than green-leaved ones. Widespread use of certain purple-leaved cultivars of generally susceptible plant species probably contributes to the perception that purpleleaved plants, overall, are preferred. Purple-leaved cultivars of redbud, European beech, smoketree, and barberry, or the purple-leaved Prunus virginiana L. `Canada Red' or Malus ×hybrida Lemoine `Jomarie' may be suitable substitutes for more susceptible purple-leaved plants in landscapes where Japanese beetles are a concern.
Mark H. Brand, Jessica D. Lubell, and Jonathan M. Lehrer
., 2011 ). In Connecticut, 25 cultivars of Japanese barberry that produce high seed yields were voluntarily banned by the Connecticut Nursery and Landscape Association and only lower fruiting cultivars may be sold after 2013 ( Connecticut Nursery and
invasive species, japanese barberry and winged euonymus. American filbert, buttonbush, northern bush honeysuckle, sweet fern, and sweet gale performed as well as the invasive species. Steeplebush did not perform as well due to powdery mildew and less than
David C. Zlesak
used as an alternative to purple and yellow-leafed barberry in regions where barberry is deemed invasive ( Lubell et al., 2011 ) or in situations in which the spines of barberry are a liability. Ninebark is relatively pest-resistant but can be
Jessica D. Lubell and Jacob A. Griffith Gardner
-sun plants, particularly those near the shoot tip, were lighter green or more yellow at the end of the study ( Fig. 2 ). In a similar study looking at green-leaved genotypes of japanese barberry ( Berberis thunbergii ) grown under shade levels of 0% to 72