Cheyenne® Mock Orange: 2020 Plant Of The Year

Cheyenne® Mock Orange is an extraordinary discovery that has become available to the gardening public through Colorado’s plant introduction program, Plant Select®. It comes into our line-up as the celebrated 2020 High Country Gardens Plant of the Year.

The history of this Philadelphus selection is fascinating. Its cultivation began long ago on the High Plains of Wyoming, as part of a larger effort that began in the early 20th century to search for beneficial plants that were well-adapted to life on the high, cold plains of the Intermountain west.

Read on to learn more about this beautiful, rugged shrub!

The History of Cheyenne® Mock Orange

In 1928, the US Congress authorized an agricultural experiment station on 2,140 acres of land near Cheyenne, Wyoming. There, the U.S. Department of Agriculture (USDA) was directed to establish the Cheyenne Horticultural Field Station, to test and propagate fruit plants, fruit trees, flowering trees, shelterbelt trees, shrubs, and vines that would be well-adapted to the conditions and needs of the semiarid or dry land regions of the U.S.

The first plantings were made in 1930, and the building construction was completed in 1931. It was a huge project, and the manpower to establish and maintain the Field Station came from residents of the area and members of the Conservation Civilian Corp. Under the direction of the Station’s first superintendent, Dr. A.C. Hildreth, who oversaw the operations from 1930 until World War II, a collection of over 20,000 Horticultural species and varieties was developed! Many were native plants from the American West, and others were collected from Asia and Europe by USDA plant explorers, including the well-known P.H. Dorsett.

This shrub was originally grown at the station for evaluation. Started from seed collected in Alberta, Canada, three plants of Philadelphus lewisii were planted along with approximately 200 plants of other Philadelphus species collected from Asia and southeastern Europe.

By the time the Field Station closed its woody plant evaluations program in 1947, all of the Philadelphus shrubs had perished – except for the three original North American plants of the yet un-named Mock Orange.

When the woody plant evaluations came to an end in 1974, the plants there were left un-irrigated to fend for themselves. Decades later, the Philadelphus lewisii survived!

Fortunately, through the efforts of plantsman and horticultural historian Scott Skogerboe of Fort Collins Wholesale Nursery and other horticulturists, cuttings and seeds were collected from the Field Station over the years.* The introduction of Cheyenne® Mock Orange is a part of this historic horticultural effort.

Bringing Cheyenne® Mock Orange into Your Garden

Withstanding the incredibly harsh growing conditions that the high plains of Wyoming could throw at it, Cheyenne® Mock Orange had proven its resiliency and superiority over other common Philadelphus in the trade. 

Blooming in late spring with a profusion of large, pure white, four petal flowers, one of the best reasons to invite Cheyenne® Mock Orange into your landscape is to enjoy the intensely sweet citrus scent of the flowers. The blossoms of this tough, hardy shrub have an amazing fragrance, making it irresistible to gardeners and pollinators alike!

As illustrated by its history, Cheyenne® Mock Orange is adaptable in its water needs, and is exceptionally cold-hardy, withstanding USDA zone 3 winter temperatures (to - 40° F). Once established, the shrub is very xeric, but is also happy with moderate watering. This hardy shrub grows well in a wide range of soil types including clay. Growing to a modest size, 6-9 ft in height and 5-8 ft wide, it does well in sun or part shade conditions, even dry dappled shade.

Cheyenne® Mock Orange is adaptable as to its place in the garden, so you can mix it into the back of the perennial border, or plant among other low-water native shrubs. It is resistant to browsing rabbit and deer, but should be protected for a few years when young.

Bring a bit of horticultural history into your yard, and enjoy the efforts of our early horticultural pioneers with this beautiful and sweetly scented flowering shrub.

Cheyenne® Mock Orange is adaptable as to its place in the garden, so you can mix it into the back of the perennial border, or plant among other low-water native shrubs. It is resistant to browsing rabbit and deer, but should be protected for a few years when young.

• As illustrated by its history, Cheyenne® Mock Orange is adaptable in its water needs, and is exceptionally cold-hardy, withstanding USDA zone 3 winter temperatures (to - 40° F).
• Once established, the shrub is very xeric, but is also happy with moderate watering.
• This hardy shrub grows well in a wide range of soil types including clay.
• Growing to a modest size, 6-9 ft in height and 5-8 ft wide, it does well in sun or part shade conditions, even dry dappled shade.

Bring a bit of horticultural history into your yard, and enjoy the efforts of our early horticultural pioneers with this beautiful and sweetly scented flowering shrub.

*Resources to learn more about the history of the High Plains Field Station and its plants:

• The Cheyenne High Plains Horticulture Research Station, by Scott Skogerboe
• The Cheyenne Botanic Gardens is developing a 62-acre public arboretum on the former historic USDA High Plains Horticulture Station: Learn more here
• A Brief History Of The Cheyenne Horticultural Field Station and the High Plains Grasslands Research Station