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Growing Tips—Help Find America's Lost Pears, Boost Your Beneficial Bugs, and More
Plants & Gardens News Volume 20, Number 3 | Fall 2005/Winter 2006
by Greg and Pat Williams
Help Find America's "Lost" Pears
Pyrus 'Brandywine' (pear). Illustration by the USDA Pomological Watercolors Collection.
U.P. Hedrick's The Pears of New York, published in 1921 by the New York Agricultural Experiment Station, is the classic work on pears grown in the U.S. in the early 20th century. In it, Hedrick described 78 of the superior cultivars of his time. But how many of these still remain?
Researchers at the U.S. Department of Agriculture's National Clonal Germplasm Repository (NCGR) have found many, but not all, of the 78. The NCGR recently published a list of the still-missing cultivars with a plea for help in locating them. The "lost" cultivars are 'Ansault', 'Brandywine', 'Dearborn', 'Duhamel du Monceau', 'Elizabeth', 'Fontenay', 'Koonce', 'Léon Leclerc' ('Van Mons'), 'Lincoln Coreless', 'Margaret', 'Mount Vernon', 'Ontario', 'Reeder', 'Riehl Best', 'Rutter', 'Souvenir d'Espéren', and 'Onondaga'. Illustrations of the pears from Hedrick's book are reproduced online at www.ars-grin.gov/cor/pony.html.
If you have information on the possible survival of any of the pears, contact Joseph Postman, USDA, Agricultural Research Service, National Clonal Germplasm Repository, Corvallis, OR 97333; e-mail jpostman@ars-grin.gov.
Source: J.D. Postman, "The Lost Pears of New York," Journal of the American Pomological Society 59(1), January 2005, 3–6 (American Pomological Society, 102 Tyson Bldg., University Park, PA 16802).
Canada columbine (Aquilegia canadensis). Photo by the Washtenaw County Conservation District.
Leafminer-Resistant Columbines
Field trials of several columbines (Aquilegia species) conducted by University of Georgia entomologists have revealed a considerable range of resistance to infestation by the commonly encountered leafminer Phytomyza aquilegivora. Problems caused by the leafminer were generally seen least on the native species Aquilegia canadensis (Canada columbine) and A. caerulea Dwarf Fantasy Mix (Rocky Mountain columbine), as well as on the Asian species A. flabellata (fan columbine). However, none of the tested plants showed a particularly high level of resistance.
Source: S.K. Braman, G.D. Buntin, and R.D. Oetting, "Species and Cultivar Influences on Infestation by and Parasitism of a Columbine Leafminer (Phytomyza aquilegivora Spencer)," Journal of Environmental Horticulture 23(1), March 2005, 9–13 (Horticultural Research Institute, 1000 Vermont Ave., N.W., Suite 300, Washington, DC 20005).
Boosting Beneficial Bugs in the Garden
It's well known that the presence of beneficial predatory and parasitic insects in a garden can help control pest insects and reduce the need for artificial sprays. However, certain landscapes, such as those in urban areas, lack the natural resources to attract a diversity of these natural enemies of pest insects. Entomologists at Purdue University and the University of Illinois recently tested the idea that planting flowers known to be attractive to various beneficial bugs (so-called "floral resource plants") can boost the bugs' local population densities in an ornamental setting.
The entomologists set up trial plots outdoors. In some plots, they created central beds of Euonymus fortunei 'Coloratus' (winter creeper) surrounded only by composted wood mulch. In other plots, floral resource plants were planted around E. fortunei beds. These plants bloomed in succession throughout the year and included Euphorbia polychroma (flowering spurge), Coreopsis verticillata 'Moonbeam' (threadleaf tickseed), Solidago canadensis 'Goldkind' (goldenrod), and Trifolium repens (white clover). Natural enemy populations were assessed each month during three consecutive growing seasons.
In most cases, natural enemy populations were higher in plots with floral resource plants, and there were indications that greater numbers of those plants were sometimes associated with somewhat higher natural enemy populations. However, removal of flowers from the floral resource plants in some plots did not result in clear-cut reductions of natural enemy populations in those plots, suggesting that flowering of the plants per se might not be the sole or even the most important factor in attracting the beneficial bugs. Still, the entomologists were able to conclude that the floral resource plants used in their trial did boost local populations of natural enemies.
Gardeners in the East and Midwest should be advised that Euonymus fortunei is invasive and should not be planted in those regions.
Source: E.J. Rebek, C.S. Sadof, and L.M. Hanks, "Manipulating the Abundance of Natural Enemies in Ornamental Landscapes with Floral Resource Plants," Biological Control 33(2), May 2005, 203–16 (Elsevier Science, 6277 Sea Harbor Dr., Orlando, FL 32887).
Use Hand Sanitizers to Preserve Insects
Hand sanitizer
If you need an easily available and inexpensive medium for short-term or even fairly long-term storage of captured insects (perhaps to transport pest insects to a diagnostic laboratory for identification), consider using a regular hand sanitizer from your local drugstore or supermarket. Pest-control industry consultant Gerald Wegner tested three brand-name hand sanitizers (Dial, Purell, and Meijer) as insect and spider preservatives and concluded that they all worked quite well. Over the course of a year, adult specimens remained "lifelike" when immersed in the sanitizers, though some immature specimens became dark and/or slightly distorted.
Easy to find and purchase, hand sanitizers also seem preferable to traditional insect preservatives containing such hazardous substances as formalin, acetic acid, and kerosene. The primary ingredients in the sanitizers include ethyl alcohol, water, carboner (an acrylic acid polymer used to thicken various cosmetic products), glycerin, and propylene glycol (also commonly found in cosmetic products). All of these ingredients are deemed safe by government regulators for regular skin contact.
Source: G.S. Wegner, "A Surprising New Medium for Specimen Preservation and Display," American Entomologist 50(4), Winter 2004, 220–21 (Entomological Society of America, 9301 Annapolis Rd., Lanham, MD 20706).
Salvia splendens 'Vista Red'. Photo by www.odla.nu.
A Super-Heat-Tolerant Salvia
Gardeners looking for an ornamental that can take scorching heat should try the annual Salvia splendens 'Vista Red'. In trials conducted at the Louisiana State University AgCenter, in Baton Rouge, three-week-old Salvia seedlings were exposed to 104°F for three hours every three days until they bloomed. 'Vista Red' seedlings maintained "acceptable" quality, while another reputedly hot-weather S. splendens cultivar, 'Sizzler Red', was considerably less tolerant of the high temperatures. Physiological tests revealed that the leaf-cell membranes of 'Vista Red' are less susceptible to heat damage than those of 'Sizzler Red'.
Source: S. Natarajan and J.S. Kuehny, "Screening Bedding Plants for Heat Stress Tolerance," Louisiana Agriculture 46(1), Winter 2005, 18–19 (Louisiana Agricultural Experiment Station, P.O. Box 25100, Baton Rouge, LA 70894).
Garden Visits Benefit the Elderly
Researchers in Finland surveyed elderly residents of a nursing home to examine the effects that visiting an ornamental garden had on their well-being. Those surveyed tended to visit the (wheelchair-accessible) garden frequently, and many said that they felt better when visiting the garden. More than 90 percent of those who were classified as depressed agreed with the statement "I feel more cheerful and alert" when visiting the garden, and about two thirds of those who were classified as depressed agreed with the statement "I sleep better at night" after visiting the garden. The aspects of garden visiting that rated highest for improved well-being included viewing the plants and animals, getting exercise and observing nature, enjoying the fresh air and garden fragrances, and social interactions.
Source: E. Rappe and S.-L. Kivelä, "Effects of Garden Visits on Long-Term Care Residents as Related to Depression," HortTechnology 15(2), April–June 2005, 298–303 (American Society for Horticultural Science, 113 S. West St., Suite 200, Alexandria, VA 22314).
Greg and Pat Williams run a farm in Gravel Switch, Kentucky, and edit the monthly gardening newsletter HortIdeas.