COVID-19 Update: The Minnesota Landscape Arboretum reopened in a limited capacity on Friday, May 1. As a key part of the University of Minnesota’s research and outreach missions, we have been working with University leadership on a phased approach to ensure visitor and employee safety as we welcome you back. Find updates and information here.
Editor’s Note: We’re celebrating our Season of Trees with Tree Tuesday on the Nature Notes blog. Come back each Tuesday for stories exploring the Arboretum’s trees and tree collections, and read personal Tree Stories submitted by Arboretum members, staff and visitors.
By Jeffrey Johnson, Landscape Gardener – Woody Plants Specialist
After the Arboretum’s inception in 1958, the land holding was a much smaller parcel that hugged old Highway 5 south of its current route across the isthmus. During those early years, staff established many tree collections to trial and display in a traditional manor of an “Arboretum” or “Trees Library” with plantings of genera, i.e. Ash (Fraxinus), Buckeye (Aesculus), Fir (Abies), etc.
Much development of what is now the front display gardens ensued during the tenure of Dr. Francis Devos, who was the Arboretum Director from 1976 to 1984. Prior to this, a Fir Collection (Abies sp.) occupied the current location of the DeVos Home Demonstration Garden and the Woodland Azalea Garden. Many of the specimen fir trees were lost to the development. But one particularly unusual accession of Fir remains: Shikoku Fir (Abies vetchii var sikoiana). It is next to the walkway between the Home Demonstration Garden and the Woodland Azalea Garden.
There are other “old” collections that now occupy the front gardens near the Snyder Education Building, Oswald Visitor Center and parking lots, including the “Old Ash Collection” just east of the Gatehouse Area. There is also an interesting grove of Tulip Trees (Liriodendron tulipifera) south of the roadway to the overflow parking lot (old Highway 5 roadbed).
A new Fir Collection was established in what was then known as the “Back 600,” the plateau acreage south of the Mountain Ash Collection on “Switchback Hill” named for a path leading up to the Nelson Shrub Rose Garden. Many of the fir planted there were moved from the original collection site.
This second try at a Fir collection was the hill west of the Nelson Shrub Rose Garden. This has primarily White Fir (Abies concolor), and also Manchurian Fir (Abies holophylla) and Arizona Corkbark Fir (Abies lasiocarpa var arizonica). The area was limited, had poor drainage and turned out to be a less than ideal site for the collection.
The latest Fir Collection with 17 specimens and 8 distinct accessions, most planted in the early 1990s, is southwest of the southern part of the Pines Collection. Unless you are a trees and shrubs nerd like me, you likely would not know it is there. There is no sign for the collection.
We are discussing plans to augment the collection with signage. We’re also hoping to expand the collection with a variety of plants from preferably wild collected seed of species from isolated populations. This would assure species is pure and uncontaminated from other species within Abies genus. Populating the collections with latest and “best” cultivars would quickly use up allocated space with the proliferation of many often untested cultivars within the past decades. It is near impossible to trial in a standardized way all cultivars of even one species with new cultivars being released frequently.
Fir are a substantial genus of evergreens in the Pinaceae family, which also includes cedars, hemlocks, larches, pines and spruces. Firs are known for spirally-arranged individual, usually flattened, soft needles of varying length. They require well drained, moist soil with a preference to slightly acid soil.
Cultivars of Fir are selected for different traits, including foliar color, shape, and size. Some cultivars are displayed in the Rock Garden (part of the Home Demonstration Garden) and the Dwarf Conifer Collection surrounding the main waterfall south west of the Snyder Education Building.
Most Fir are excellent landscape evergreens for Minnesota. Given well-drained, friable soil, many species and cultivars will thrive in our USDA Hardiness Zone 4b. Considered large evergreens, the species are highly conical specimens to old age, much like spruce (Picea). Dwarf cultivars are grafted. Their flattened needles are much softer to the touch than spruce and do not have nearly the pest issues.