Siberian Elm in Holbrook, Arizona

Holbrook, Arizona is striving to achieve a Tree City USA designation from the National Arbor Day Foundation. This designation provides a number of benefits including enhanced public image to visitors and businesses and citizen pride in the community. The Holbrook elm project helps Holbrook meet the qualifying standards for this award by showing the city has a community forestry program.

Elms (Ulmus sp.) as a group, offer great potential as an urban species. There is considerable effort devoted to breeding and genetic improvement of elms. A large number of new varieties are likely to be released over the next decade. However, many of the new and existing varieties have not been tested for tolerance to environmental conditions or the elm leaf beetle (Pyrrhalta luteola). An innovative collaborative working group has come together in Holbrook Arizona to do just that. Cooperators in this exciting initiative include:

Michael R. Wagner, Regent's Professor
School of Forestry
Box 15018
Northern Arizona University
Flagstaff, Arizona 86011

Frederic D. Miller, Extension Educator
Urban Integrated Pest Management
University of Illinois
Countryside Extension Center
6438 Joliet Rd
Countryside, Illinois 60525

Stephen J. Campbell, Associate Agent
University of Arizona
Cooperative Extension, Navajo County Office
402 E Hopi Dr
Holbrook, Arizona 86025

Ron Romatzke
Urban and Community Forester
Arizona State Land Department
1616 West Adams
Phoenix, Arizona 85007

R. Alan Roes
Public Works Department
City of Holbrook
PO Box 970
Holbrook, Arizona 86025

Plantation. In Arizona, Siberian elm (Ulmus pumila) is the most widely planted elm species. Recent introductions of the elm leaf beetle have devastated populations of this elm species in many rural communities in the northern part of Arizona.

Damage to an elm branch from the feeding of the elm leaf

Other scientists have examined resistance to elm leaf beetle, but much of this work is conducted in a laboratory setting with a limited number of varieties. We are conducting similar tests at a plantation at the Navajo County Fairgrounds in Holbrook, Arizona. Our work is performed under field conditions and will test 28 genotypes of elms. This makes our work the broadest test of the elm leaf beetle under field conditions in the U.S. and the only such test in the harsh conditions of Arizona. This work will provide more elm planting options for a region in Arizona that is currently limited to the planting of the environmentally tolerant, but highly elm leaf beetle susceptible, Siberian elm.

Demonstration Planting. We are using the information gained from our study of elm species and cultivars and their tolerance to construct a demonstration planting of elms in the City of Holbrook. We hope that individuals in the community will use the information we are providing and will landscape with species of elm that are better matched to Holbrook's harsh conditions and elm leaf beetle population. 

Future of the Holbrook Elm Project

This project is supported through grant funds provided by the Urban and Community Forester, Arizona State Land Department and the Northern Arizona University School of Forestry. If grant funding can be maintained, we hope to expand this web page to include several extension publications prepared specifically for urban forests in east central Arizona. We also hope to prepare leaflets on elms, elm leaf beetle, and watering urban trees in this area. Finally, we are soliciting the assistance of community groups and individuals in east central Arizona to join our efforts.

Other sites of interest:

Last Updated ( Thursday, 10 July 2008 )