Dependable Landscape Trees from the Colorado State University Arboretum

Posted by: James E. Klett, Extension Horticulture Specialist

A new publication (Bulletin XCM -150), Dependable Landscape Trees from the Colorado State University Arboretum, was recently published by Colorado State University Extension authored by Sarah Shaub, M.S and James Klett, Ph.D.  It is a collaboration between Colorado State Extension, Colorado State University College of Agricultural Sciences and Colorado Agriculture Experiment Station.  

The book is available from CSU University Resourse Center, 115 General Services Building 4061 Campus Delivery, Fort Collins, CO 80523, Phone (970) 481- 6198, or www.csuextstore.com. Cost: $19.95, plus shipping and handling. 

The Colorado State University Arboretum is located at the Plant Environmental Research Center (PERC) located in the southwest corner of the main campus (630 W. Lake Street in Fort Collins).  The main objectives of the arboretum are to determine which plants are suitable for growing in the Rocky Mountain area and to display the plants for teaching and public viewing.  The PERC arboretum contains more than 1,100 different plants with an additional 120 taxa located at an additional six acre arboretum on Center Avenue in Fort Collins.  The plants discussed in this publication are based on data collected between 1997 and 2012.  Every plant in the arboretum is evaluated every two years using a standard evaluation form comprised of 31 parameters relating to plant characteristics, aesthetic value, plant health, insect and disease problems and cultural and maintenance problems.

The plants discussed in this publication needed to be growing a minimum of 10 years in the arboretum and then ranked on two evaluations parameters: overall health and aesthetic value.  Plants were ranked and given an assigned ranking; a minimum point cut-off eliminated less suitable plants for the region.  This selection process yielded the 225 trees discussed in the publication.  Both deciduous and evergreen trees are arranged by scientific name in alphabetical order of each section in the publication.  Each plant entry lists the years transplanted, 2012 height and width, mature height and width, growth habit, landscape uses, flowers, fruit, fall color, pests and potential problems.

Along with the list of general plants characteristics, a description of each plant is provided.  This is a summary of the main landscape features of the plant.  Entries for tree cultivars include a shorter description, with the primary information provided being the main characteristics of the cultivar that differ from the species. 

The performance section of each entry is a summary of the evaluation data for each numerous plant.  If any characteristics of the arboretum are different from what is expected, it is indicated here.  Photographs of most of the trees are adjacent to the plant characteristics. 

There are also numerous appendixes in the book including: list of plants that did not meet the criteria for number of years in the arboretum, list of plants still under evaluation, list of trees by flower color, fruit color, landscape uses, mature size and fall color.  Descriptions of the plants normally have three photos accompanying the description often showing growth habit, flower and fall color.

Many foundations and organizations contribute yearly funding to operate the arboretum along with numerous nurseries and botanic garden providing plant material. This is a must-have publication for anyone recommending landscape trees for the Colorado and Rocky Mountain Area.