UACES Facebook 'Arnold's Promise' Witchhazel - February 16, 2018

Plant of the Week: 'Arnold's Promise' Witchhazel - February 16, 2018

The University of Arkansas System Division of Agriculture does not promote, support or recommend plants featured in "Plant of the Week." Please consult your local Extension office for plants suitable for your region.

Each week since 1997, Dr. Gerald Klingaman has offered readers a unique window as he chronicles of the social history of plants.

"What always interested me was the background of the plants and how they got there and the people involved in bringing them forward," he said. 

Klingaman, a retired extension horticulturist who is now operations director for the Botanical Garden of the Ozarks in Fayetteville, Arkansas, has created is a library of hundreds of plant histories that run in newspapers across the state and have become a favorite of gardeners in Arkansas and beyond. We hope you'll enjoy our extensive archive of his works and return each week to see what's new. 

Plant of the Week: Arnold’s Promise Witchhazel
Latin: Hamamelis x intermedia ‘Arnold’s Promise’

As a dedicated, life-long folkie, I’ve often marveled at the talent many of the traveling troubadours display, yet they remain almost unknown. The same thing happens with plants. Spectacular plants such as Arnold Promise witchhazel (Hamamelis x intermedia) have great garden merit, yet they are hard to find in traditional nurseries and shunned by the big box stores.

Hamamelis x intermedia 'Arnold's Promise' GK  3 6 10
SPRING WELCOME — Arnold Promise witch hazel is a beautiful reminder that spring has arrived.

Six species of witchhazels, members of their own family, are described with three found in North America and two in China and Japan. Arkansas has the fall flowering common witchhazel (Hamamelis virginiana) and the more common spring flowering Ozark witchhazel (H. vernalis). Both are found along streambanks of the Ozarks and Ouachitas.

Witchhazels are large deciduous shrubs or small trees. Only common witchhazel, which blooms from October through December, blooms in the fall. All other species are spring blooming, as long as you consider January part of the spring season. Arnold Promise has an upright form with plants reaching 20 feet and producing blooms from mid-February through early April.

Arnold Promise witchhazel flowers appear as a two-inch-wide cluster of yellow, strap shaped pieces of wrinkled confetti. If you tease the cluster apart, you will notice that individual flowers have four narrow petals, each about three-quarters of an inch long that emerge from a short, cupped calyx that is red-tinged during the first part of its life. On freezing days, the flowers shrivel up, only to stretch back out as the temperatures warm.

The fruit is a hard fuzzy nutlet which opens at one end and disperses the seeds considerable distance when the structure dries in late summer. Pollination is accomplished by various species of flies and bees that are not deterred by cold weather.

Arnold Promise is a personal favorite because I get to do some name dropping about a few of my horticultural heroes. It is a hybrid between the Chinese witchhazel (H. mollis), which the eminent plant explorer E. H. Wilson collected in western China in 1908, and an unidentified Japanese witchhazel (H. japonica), possibly collected by Professor Charles Sargent during his trip to Japan in 1892.

In 1928, William Judd, who probably had one of the best jobs in horticulture as a propagator at the Arnold Arboretum, collected and planted seeds from Wilson’s introduction. Seven seedlings were planted but only two survived long enough to get planted out in the arboretum for evaluation. In 1945 Alfred Rehder, the Arboretum’s renowned tree guy, described the hybrid species as having characteristics intermediate between the two parents.

In October 1963, Donald Wyman, the horticulturist for the Arboretum and author of the books that began my lifelong love of plants, officially announced the introduction of Arnold Promise witchhazel. Today it is still the most common of the hybrids and amongst the best of the many that are offered.

Arnold Promise has the best features of both species. It retains the high bud count and fragrance of its Chinese parent while incorporating the longer petals and superior winter hardiness of its Japanese father. It also drops its leaves in the fall, producing a clean plant that does not have hanging brown leaves hiding the blooms when they open in the spring.

Witchhazels are hardy from zones 5 through 8 and well suited for use as a specimen in medium shade or full sun. Because they bloom early and the flowers are fragrant and not as visual from great distance, they should be planted where they can be viewed close up. Fall planted container grown plants have worked best for me.

For more information about horticulture or to see other Plant of the Week columns, visit Extension’s Website, or contact your county extension agent. The Cooperative Extension Service is part of the U of A System Division of Agriculture.


By: Gerald Klingaman,Retired
Extension Horticulturist - Ornamentals
Extension News - Feb. 16, 2018