Perennial Garden

In the fall of 2016 the Perennial Teaching, Research, and Demonstration Garden was relocated from the old Plant Environmental Research Center (PERC) to its new home next to the CSU University Center for the Arts on Remington and Pitkin. The Perennial Garden was originally started at the PERC site in 1980 by Dr. Jim Klett and has grown over the decades to approximately 1000 taxa. Three of each taxa were moved to the new location for a total of approximately 3,000 plants. In addition to the 3,000 herbaceous perennials moved, 19 trees were saved and relocated.

Heritage Arboretum & Garden

The Heritage Garden & Arboretum Collection is 5.5 acres and was established over thirty years ago. It has the largest collections of woody plants in the region with over 1,100 different taxa represented. The Heritage Gardens showcase the agricultural heritage from six major regions in Colorado. Presently, a computerized method for collection, storage, and retrieval of information on plant performance has been implemented for all the woody plants. New plants are continually being added to and evaluated in the collection.

Read the Heritage Arboretum reports or learn more about woody plant research: http://woodyplants.colostate.edu/

Centre Avenue Arboretum

The main objectives of this area are to determine which woody plants are best suited for growing in the Rocky Mountain area and display these plants for public research and teaching purposes.

It began in 2003 with the need to relocate some trees at the Heritage Arboretum when the Summit Hall dorm was constructed. The trees were moved to the Centre Arboretum site which is approximately 6 acres. The plants at both the Heritage Arboretum and the Centre Arboretum are now part of the overall campus arboretum effort but are still managed by the Department of Horticulture and Landscape Architecture. Both areas have plants that were donated to the woody plant evaluation program from generous support from members of the Green Industry and other public gardens. Between the two sites, the arboretum at CSU has the largest collections of woody plants in the region with over 1,100 different taxa represented. Each plant is evaluated every two years and the report is available for free and online at http://woodyplants.colostate.edu/. New plants are continually being added and evaluated in the collection.

The plants at the Centre Avenue Arboretum are strictly trees while the Heritage Arboretum also includes many shrubs. The other main difference between the two sites is that the Centre Avenue site is organized in straight rows with a drip irrigation system while the Heritage site is planted in a more informal pattern by plant family and is irrigated with hoses and sprinklers. Both areas have each plant labeled with both scientific and common names and the label is usually on the north side unless there is a compelling reason (such as crowded by a nearby plant) to have it on the east or west. Both sites are free and open to the public during daylight hours.

Annual Flower Trial Garden 

The outdoor display and test areas at the Annual Flower Trial Garden were established to allow students, researchers, industry representatives, homeowners and extension personnel to learn, teach and evaluate through horticultural research and demonstration projects conducted in the unique environmental conditions of the Rocky Mountain/High Plains region.

Read more about the Flower Trial Gardens: http://www.flowertrials.colostate.edu/

The Oval

The Oval elm collection dating from 1881, is preserved for the long-term benefit of university and has continuing research value in finding efficacious treatments for evolving exotic pests of elm.

Fun Facts & History:

When were the original Oval trees planted?

• The center double row of trees (the tree allee) were originally planted in 1881 as part of a larger tree planting effort on campus. This was almost 30 years before the Oval as we know it today was proposed as part of the 1910 Master Plan by W.W. Parce, a landscape architect with an office in Boulder. Most of these 1881 trees survive today, but many have been replanted over the last 137 years, and are now of equal size with the originals.
• The Elm trees ringing the exterior of the Oval were planted between 1922 and 1927 in successive annual plantings.  Many of these trees are now larger than the original 1881 planting. 

What kinds of trees are in the Oval?

• Almost all of the trees are American Elm – Ulmus americana

What differences are there between the original trees and the trees planted today?

• It is apparent that the plantings of 1881 and of the 1920s were seedling American Elm, and unlike the clonal varieties of American Elm sold in the nursery trade today, each is genetically unique. As a result, some of the trees have unique characteristics, and some tree lovers would say personalities.

What impacts have there been to the health of the Oval trees over the years?

• The Oval trees have survived many fall and winter ice and snow storms largely intact, but there were two periods of extreme crisis, which could have resulted in the loss of the Oval elms that exist today. 
• Dutch Elm Disease (DED) was an extreme risk to the Oval starting in the 1970s when the disease arrived in Colorado. Without active intervention, including a sanitation protocol, Dutch Elm Disease is fatal, and by one account of the estimated 77 million elms in north America in 1930, 75 percent were lost by 1989. Most of the Oval trees have survived Dutch Elm Disease, but there have been loses over the years, even in the last 15 years. The Elms are monitored for signs on the disease, and if the disease is confirmed the tree is immediately removed and isolated from adjacent trees by trenching around the infected trees. The trees are of such size, that their roots are intertwined and likely grafted together in places allowing the disease to be spread from tree to tree.
• In the 1990s a study identified the Oval Trees as being in decline. A lack of funding for ongoing maintenance and the use of the Oval grounds for multiple events during the school year and summer had placed the trees in vulnerable state. The trees were suffering from equal parts neglect and the overuse of the turf which contributes to soil compaction which is directly related to tree heath. A steering committee was brought together to recommend a new plan for the Oval, public meetings were held, and emotions ran high as two competing visions emerged. One vision called for the removal of all Oval Trees and a replanting of 98 elms in their original positions to maintain the original Oval pattern. A second vision called for the addition of multiple species of trees in an irregular pattern to be planted over time to give the Oval both species and age diversity, while maintaining existing elms, but replanting them in the original pattern. In the end neither vision was implemented, and 20 years later the Oval trees are arguably in a more sustainable state that they were 20 years ago, and the Oval remains the most iconic space on campus.

What recent efforts have contributed to the success of the Oval?

• Holding events regularly on the Oval had accelerated compaction of the soil; therefore, the elimination of non-CSU events (such as Taste of Fort Collins and an annual Dog show among others) from the Oval grounds and limiting other events has helped to manage and mitigate compaction.
• No structures are allowed to be built on the Oval, including benches, and nothing can be hung from the branches of the Oval trees.
• The Oval is free of lighting and electrical receptacles, and although it is sometimes suggested that holiday lights be hung from these trees, the extensive trenching needed to bring power to each tree would likely kill or significantly shorten the lives of these trees. 
• Trees are annually treated to control a scale insect that saps the strength of the trees.
• Trees are continually monitored for Dutch Elm Disease during the growing season.
• Dutch Elm resistant, and scale resistant elms have been planted when older elms are lost, maintaining the historic Oval tree pattern.
• All of the Oval elms are pruned on a three-year interval for tree heath, and safety of the campus community.

How much does it cost to sustain the Oval trees?

• On an annual basis it costs more than $50,000 to sustain the Oval trees. Annual treatments for insect (scale) control is $30,000, and the last three-year cycle of pruning cost $130,000. The Oval Preservation Fund proceeds go directly towards these costs, but cover only approximately 10% of costs on an annual basis.

What is the Oval Preservation Fund?

• Primarily it is a vehicle to preserve the existing Oval Elm trees in a safe and healthy condition for future generations. As these historic trees are lost through extreme age, disease, or storm damage, the Oval Preservation Fund helps to plant new Elm trees in their places to insure the Oval composition endures into the future.

SOURCE – Oval Trees 101: Do you know their history? (October 18, 2016)