LANDSCAPE SPRINKLER DESIGN Monday, March 24, 8 a.m. to 5 p.m. NHS Hall, Center for Urban Horticulture $75; fee includes Course Notebook, lunch Pre-registration required; size limited to 30 participants INSTRUCTOR: Robert Walker, Professional Engineer and Landscape Irrigation Professor at the Irrigation Training & Research Center of California Polytechnic State University — San Luis Obispo PROGRAM OVERVIEW: This entry level intensive work- shop will provide practical information on microirrigation design and maintenance concepts. The program begins with a review of terminology and basic irrigation concepts, and then provides detailed coverage on hydraulics of hoses, emitters, and sprayers, equipment selection and system maintenance, and matching equipment to plant materials and other irrigation stations. The explanations and examples provided, along with the accompanying course notebook, should enable participants to design and maintain site-appropriate and resource efficient systems. Questions on specific site situations or equip- ment concerns will be encouraged. PROGRAM OVERVIEW: This entry level intensive work- shop will provide practical information on key sprinkler Brigation design concepts. The program begins with a review of terminology and basic irrigation concepts, and then provides detailed coverage on valves, piping, pipeline sizing, sprinkler selections, designing blocks, and application rates. The explanations and examples provided, along with the accompanying 87-page course notebook, should enable participants to design site- appropriate and resource efficient sprinkler irrigation systems. Questions on specific site situations or equip- ment concerns will be encouraged. MICROIRRIGATION FOR LANDSCAPES Tuesday, March 25, 8 a.m. to 5 p.m. Douglas Classroom, Center for Urban Horticulture $75; fee includes Course Notebook, lunch Pre-registration required; size limited to 30 participants INSTRUCTOR: Robert Walker, Professional Engineer and Landscape Irrigation Professor at the Irrigation Training & Ilesearch Center of California Polytechnic State university — San Luis Obispo PRUNING LANDSCAPE TREES & SHRUBS Thursday, March 27, 9 a.m. to 3 p.m. Graham Visitors Center, Washington Park Arboretum $30; fee includes lunch Pre-registration required; size limited to 30 participants INSTRUCTOR: Dr. Ray Maleike, Extension Horticulturist, Washington State University-Puyallup International Society of Arboriculture CEU’s pending. PROGRAM OVERVIEW: This entry level intensive work- shop will begin with classroom lectures reviewing pruning tools, techniques, and timing relative to training, preserv- ing and renovating landscape trees and shrubs. The program then moves out into the Arboretum for demon- strations and discussions of pruning techniques for specific plant groups, including rhododendrons and azaleas, other common deciduous and evergreen shrubs, and deciduous, broad-leafed evergreen and coniferous trees. OTHER EDUCATIONAL OPPORTUNITIES EDMONDS COMMUNITY COLLEGE WINTER COURSES: Soils & Plant Nutrition; Turf Equipment & Tools; Land- scape Studies; Herbs; Mixed Border Practicum; Plant Propagation; Plant Collecting; Vines; Conifer Problems; Wood Projects; Landscape Design 1; Construction Design; Conifer Identification; Pest Management Principles; Pruning; Landscape Appreciation; Turf Physiology; Grafting; Greenhouse Design & Management; Professional Turf; Bidding & Estimating; Landscape Renovation; Drip Irrigation; Large Scale Irrigation. For registration informa- tion, call the Admissions Office at (206) 640-1372. LAKE WASHINGTON TECHNICAL COLLEGE WINTER COURSES: Urban Forestry; Soil Science; Pruning & Landscape Renovation; Native Washington Plants; Winter Plant Identification; Home Orchard Pruning; The Winter Garden; Selecting Plants for Residential Home Sites. Call (206) 828-5600 for more information. SOUTH SEATTLE COMMUNITY COLLEGE WINTER COURSES: Winter Plant Identification, Landscape Design 2; Horticulture Science 1; Horticulture Science 2; Soils; Pruning; Plant Propagation; Small Business Manage- ment; Small Engine Repair; Evaluation & Management of Hazardous Trees; Landscape Contracts & Specifications; Landscape Design 5. To register, call the Horticulture Department at (206) 764-5336. PROHORT BOOKSHELF by Laura Lipton, CUH Horticultural Librarian Crop Protection Guide for Tree Fruits in Washington, by Washington State University Cooperative Extension. Pullman: Cooperative Extension, Washington State University, 1996. Directory of Gardening Resources, by the Garden Club of America, Horticulture Committee and Jeanne Will. New York: The Garden Club of America, 1994. Horticulture Gardener’s Desk Reference, by Anne Moyer Halpin. New York: Macmillan, 1996. Know It and Grow It III: A Guide to the Identification and Use of Landscape Plants, by Carl E. Whitcomb. 3rd ed. Stillwater, OK: Lacebark, 1996. A Manual of California Vegetation, by John 0. Sawyer and Todd Keeler-Wolf. Sacramento: California Native Plant Society, 1995. Native Gardens for Dry Climates, by Sally Wasowski and Andy Wasowski. 1st ed. New York: C. Potter, 1995. Native Plants in the Coastal Garden: A Guide for Garden- ers in British Columbia and the Pacific Northwest, by April Pettinger. Vancouver: Whitecap Books, 1996. Restoring Diversity: Strategies for Reintroduction of Endangered Plants, edited by Donald Al Falk, Constance I. Millar, and Margaret Olwell. Washington, DC: Island Press, 1996. The RHS Plant Finder, by Chris Philip and Tony Lord. 10th ed. Whitbourne: Hedmain, 1996. Rodale's Pest & Disease Problem Solver, by Linda A. Gilkeson, Pam Peirce and Miranda Smith. Emmaus, PA: Rodale Press, 1996. Hours are Mondays, 9 a.m. to 7:45 p.m., Tuesdays through Fridays, 9 a.m. to 5 p.m., except holidays. Phone: (206) 685-8033 for further information. New titles of interest: The 400 Best Garden Plants: A Practical Encyclopedia of Annuals, Perennials, Bulbs, Trees, and Shrubs, by Elvin McDonald. 1st ed. New York: Random House, 1995. Canada ’s Vegetation: A World Perspective, by Geoffrey A. J. Scott. Montreal: McGill-Queens University Press, 1995. The Canadian Plant Sourcebook 1996, by Anne Ashley and Peter Ashley. Ottawa: A. & P. Ashley, 1996. Seeds: The Definitive Guide to Growing, History, and Lore, by H. Peter Loewer. New York: Macmillan, 1995. Sensitive Plants and Noxious Weeds of the Mt. Baker- Shoqualmie National Forest, by Laura L. Potash. Port- land: US Dept, of Agriculture, Forest Service, Pacific Northwest Region, 1991. Trees to Know in Oregon, by Edward C. Jensen and Charles R. Ross. Corvallis: Oregon State University Extension Service, 1994. Vegetation and Slopes: Stabilization, Protection and Ecology, edited by D. H. Barker. London: Thomas Telford 1995. Abstract thinking: ^^Current Research Abstracts of Interest Compiled by Dave Stockdale Abstracts reprinted here were selected to represent the broad variety of topics of interest to our readership and to stimulate thinking and debate and are not intended as endorsements of the research or researchers cited. We suggest that you read the complete articles to fully evaluate the merits of the information provided relative to possible applications to your work situation. All journals cited are available at the Miller Library at CUH. Replacing Soil in the Root Zone of Mature Trees for Better Growth Gary W. Watson, Patrick Kelsey, and Klaus Woodtli. Journal of Arboriculture 22(4): 167-173. July, 1996. Soils were replaced in various patterns within the root zone of mature landscape trees as an alternative to surface mulching. Care was taken to minimize root damage, by careful positioning of the excavations or use of hydraulic excavation procedures. Tree roots grew better in new soil mixes than in original soil, exhibiting up to 320% increase in fine root density and up to 68% increase in rooting depth. Declining annual growth rate trends were reversed in 7/7/a and Platanus. Soil replacement has potential as nother useful tool for treatment declining trees. Height, Caliper Growth, and Biomass Response of Ten Shade Trees Species to Treeshelters D. W. Burger, G. W. Forister, and P. A. Kiehl. Journal of Arboriculture 22(4): 161-166. July, 1996. Ten tree species common to the California landscape were grown from liners with or without treeshelters in the landscape for two years. Periodic (every two months) height and caliper measurements were taken and, at the end of two years, all trees were harvested for fresh and dry weight biomass determinations. Response to the treeshelter microenvironment was species dependent. Height was greater for sheltered versus unsheltered trees during the first 30 to 250 days for all species. After two years, Ginkgo biloba and Pinus canariensis trees grown in shelters were taller than their unsheltered counterparts. Stem caliper was often reduced for shel- tered trees. Treeshelters may be useful for tree estab- lishment in the landscape, but should be removed once the tree has grown out of it. Staking likely will be required after removal of the treeshelter. Polyethylene Plastic Wrap for Tree Wounds: A Promoter of Wound Closure on Fresh Wounds Dennis N. McDougall and Robert A. Blanchette. Journal of Arboriculture 22(5): 206-210. September, 1996. Tree wounds are often accompanied by the dieback of uninjured cambium at the edges of the wound. Dieback increases wound size and lengthens the time that xylem is exposed and susceptible to colonization by decay fungi. Wrapping new wounds with polyethylene plastic sheeting (PEP) can reduce die-back and promote the formation of callus tissue. Fresh wounds on aspen and maple wrapped with PEP had significantly less dieback than unwrapped wounds after 14 weeks. When PEP treatment was delayed one week or longer, there was no difference in wound size. Fresh wounds of aspen wrapped with PEP for one week were significantly smaller than unwrapped wounds after 15 weeks. In maple, two weeks of wrapping with PEP was required to improve wound closure. The use of PEP on wounds of birch did not affect wound size. Wounds of aspen continuously wrapped for two years with PEP did not have more colonization by decay fungi than untreated control wounds. ProHort Seminar Registration Landscape Sprinkler Design Microirrigation For Landscapes Pruning Landscape Trees & Shrubs $75 $75 $30 Yes, I require a vegetarian meal option TOTAL: $_ Group Rates: 5 or more persons, less 20%. Group registrations must be accompanied by ONE check or purchase order at least 1 week in advance. Portion of fees may cover refreshments and speaker expense. Make checks payable to the University of Washington; receipts available at the door. Mail payment and registration to: UW Center for Urban Horticulture, ProHort, U. of Washington, Box 354115, Seattle, WA, 98195-4115. For further information, call (206) 685-8033. Name/Company Name Address City State Zip Code Daytime Phone Evening Phone To request disability accommodation contact the Office of the ADA Coordinator at least ten days in advance of an event: (206) 543-6450 (voice); (206) 543-6452 (TDD); (206) 685-3885 (FAX), access@u. washington.edu (email). Fertilizer, Irrigation and Root Ball Slicing Affects Burford Holly Growth After Planting Edward F. Gilman, Thomas H. Yeager, and Diane Weigle. Journal of Environmental Horticulture 14(3):105-110. September, 1996. Dwarf burford holly (Ilex cornuta ‘Burfordii Nana’) fertilized with 22.1 g N/container/yr of nitrogen during production in the nursery generated more new shoot weight but less root weight after transplanting to a landscape than those receiving 14.8 g N/container/yr. Slicing the root ball at planting, compared to not slicing, resulted in comparable regenerated root weight but reduced new shoot number, new shoot dry weight and new shoot to regenerated root dry weight ratio when irrigation was not applied daily after transplanting. Although irrigation frequency did not impact total weight of regenerated roots into landscape soil, more roots grew from the bottom half of the root ball when plants were irrigated periodically after planting than when plants received daily irrigation. Plants irrigated other than daily produced fewer shoots and less shoot weight than those receiving irrigation daily after trans- planting. When plants were without irrigation for four or six days the first week after transplanting, those planted without the nursery container on the root ball were more stressed than those planted with the container still on the root ball However, two weeks later, plants without the nursery container were less stressed due to root growth into landscape soil. The University of Washington Center for Urban Horticulture is dedicated to research, teaching, and public service concerning the selection, management, and role of plants and of ecosystems in urban landscapes. College of Forest Resources Center for Urban Horticulture University of Washington Box 354115 Seattle, WA 98195-4115 09-9615-122 NONPROFIT ORG. U.S. POSTAGE PAID SEATTLE, WA PERMIT NO. 62