Taxonomy and Botany of Witch Hazel Shrubs
Plant taxonomy classifies the witch hazel shrubs treated here as Hamamelis x intermedia 'Arnold Promise.' The cultivar name is, as always, the name in single quotation marks. This type is a hybrid plant, being a cross between H. japonica (a Japanese species) and H. mollis (a species native to China). Further complicating its parentage is the fact that this cultivar is often grafted onto the rootstock of H. virginiana; thus its tendency to produce unwanted suckers in some cases (see below).
Arnold Promise witch hazel plants grow as deciduous flowering shrubs. However, you will often hear witch hazels referred to as "trees" because, if left unpruned, they can grow to be rather tall; moreover, the wild plant native to North America, H. virginiana, does grow as a small tree.
Arnold Promise witch hazel shrubs are vase-shaped and may reach heights of 12 feet or more with a similar spread, although they can easily be kept much shorter via pruning. Fall foliage is yellow at worst, orange at best (grow it in full sun to achieve optimal fall color). The flowers bear a warm, spicy fragrance; the smell conveys a sense of dryness, as when you smell clothing that has just come out of the clothes dryer. These blooms precede the leaves, blooming in late winter to early spring. The fringe-like petals on these yellow flowers resemble small strips of paper that have just exited from a shredder. From a distance, one could mistake witch hazel plants for forsythia (another early bloomer with yellow flowers). In fact, as with forsythia, people sometimes force the flowers of witch hazel plants.
Planting Zones, Sun and Soil Requirements
Witch hazel plants can be grown in planting zones 5-8.
Ideally, grow witch hazel plants in full sun to partial shade and in a well-drained, acidic soil amended with compost. But these bushes do display some clay-tolerance. Understory trees in the wild, witch hazel shrubs are suitable for woodland gardens, although you will sacrifice some blooms and some fall color if you do not grow your witch hazel plants in full sun.
Outstanding Feature, Uses in Landscaping
Perhaps more important than the beauty of Arnold Promise witch hazel's floral display is its timing: blooming so brightly as it does in March (zone 5) when the landscape is generally still in its dull winter doldrums, this bush is a must-have for the four season landscape. This bush is valued as one of the earliest-blooming shrubs of spring in the North.
Witch hazel plants are showy enough when in bloom to serve as minor specimen plants ("minor" only because, during spring, after blooming is finished, and during summer, the bushes are rather ordinary-looking, although the vase-shaped form will be valued in winter by those who appreciate subtleties). Mix them into a bed of other deciduous bushes, situated within sight of a window. That way, you can enjoy an unimpeded view of these beauties in late winter to early spring (all you will see is an eruption of yellow in the midst of a forest of bare branches).
Pruning and Other Care Facts
Prune Arnold Promise witch hazel shrubs to shape them, as desired, after they flower in spring. Many gardeners, however, provided that sufficient space is available, largely avoid pruning and just let their bush grow as it wants to, since they prefer the natural shape that the plant will develop on its own. As with all shrubs, though, any time is a good time to prune out dead or diseased branches, or one that rubs against another branch. Some varieties will produce suckers, and these should be pruned out in late fall. For winter protection and to shade the roots from summer's heat, mulch around your bushes. Keep the soil evenly moist, otherwise, the leaves may turn brown (known as "leaf scorch") during a hot summer, spoiling any chance you would have had for a good fall-foliage display. Mulch will also help in this regard, as a 3-inch layer of mulch around the bush will conserve moisture and help keep the soil from drying out. To fertilize, all one need do is occasionally work some extra compost into the ground around the plant.
Other Types of Witch Hazel and Meaning of the Name
Eastern North America has an indigenous witch hazel tree, Hamamelis virginiana, or "common" witch hazel. The medicinal benefits of the bark of these witch hazel trees are well known through the "witch hazel" liquid we buy at pharmacies to use as an astringent. Unlike its Asian cousins and their hybrid, Arnold Promise, common witch hazel trees bloom in fall. But a second type of witch hazel, H. vernalis, or "vernal" witch hazel is also found in North America, in the southern part of common witch hazel's range. As its common name suggests, the vernal type blooms in spring.
European settlers in the New World used the branches of witch hazel trees as divining rods for dowsing, which is the basis for one of the explanations as to how witch hazel trees received the "witch" part of their name. For the name ultimately derives from the Anglo-Saxon wych, meaning "bend" -- which is just what a divining rod is supposed to do when it detects water. But religious leaders had given dowsing such a bad name over the years that it was apparently easy to corrupt the name into "witch" (another name for divining is "water witching").
Witch hazel is sometimes spelled with a hyphen ("witch-hazel") to indicate that it is not a true hazel. Corylus is the genus name of true hazels.
So why the reference to "hazel" in the name, if it is not a true one? For one thing, the hazel had been one of the trees used in Europe for dowsing. In addition, the bush's namers may have found a resemblance to the leaves of the true hazels, such as contorted hazelnut.