Winter Gardening

Curator Report

By Allen Lacy

Although winter may bring days of drizzle or snow, it is actually the season when some of the most interesting woody plants are at their best. There are even plants whose season of bloom is precisely winter.



Bright, autumnal colors—in February

Those who habitually  refer to January and most of February as “the dead of winter,” may learn better by visiting an arboretum like the Linwood Arboretum. Here they will find evidence that a mid-winter garden can be beautiful and interesting, provided that plants have been selected with an eye toward their performance at this time of year.

Even from a distance, our own arboretum is colorful, not drab. The colors represented in the entrance berms at the corner of Wabash and Belhaven Avenues even rival the shades and hues of autumn at its peak,  thanks to some truly stand-out shrubs. From a block away, our little colony of red-twig dogwoods (Cornus sanguinea) gleam brightly even on a dour and overcast day. These are not grown for their flowers, which are inconspicuous, but for the color of their branches. In run-of-the-mill varieties, these are a somber garnet, nothing at all special, but the torrid names of our two cultivars. ‘Arctic Flame’ and ‘Midwinter Fire’ correctly suggest their dramatic presence in the landscape. Together, they meld bright yellow and coral  pink, flaming into hot red at their tips.

To see these two spectacular red-twigs is to want them. And, as a historical matter of fact, they were the first two shrubs selected, after Hella and I saw them in 2007, at the entrance to Pleasant Run Nursery, a wholesale source of many of our best plants.

These dogwoods have nearby competition in our arboretum from one of the best cultivars of  Nandina domestica, for year-round beauty. ‘Harbor Dwarf’, as its name suggests, is a diminutive shrub that will not outgrow its assigned space in a small garden. In winter, its fresh green foliage is transformed into shades of burgundy and maroon, like the red-twigs a real eye-catcher.

But flowers, as well as colorful woody parts and foliage, also enliven our berm in mid-winter. For at least six weeks beginning in early January winter Jasmine (Jasminum nudiflorum) blossoms prolifically. Commonly planted in the South, this sprawling, clambering shrub is perfectly winter-hardy in our part of Zone 7 as well. Its five-petaled, primrose yellow flowers with scarlet calyxes lack the perfume typical of its genus, but this is a small defect, considering its abundant flowering in winter. Extremely vigorous, it requires a measure of caution lest it develop high territorial ambitions. Its lax stems tend to root where they touch ground. Severe pruning once or twice a year controls it, however, and rooted cuttings may be passed on to friends eager for mid-winter bouquets.

Other winter-blooming shrubs are our collection of cultivars of the winter heath, Erica x darleyensis. These are close look-a likes of heather or ling (Calluna), except that heather blooms in summer.The winter heaths are evergreen, and covered for months with tiny egg-shaped buds and flowers, mostly in muted shades of rose, lavender, and creamy white. Berms are their ideal location, as their prime cultural necessity is drainage, drainage, and more drainage,  plus a little shearing after bloom to keep them tidy.

Our berm and its plants draw the eye beyond themselves, toward other plants,including most notably, until the robins find their flamboyant berries, toward our native deciduous hollies (Ilex verticillata). We are growing two cultivars. ‘Winter Red’ is aptly named, although ‘Christmas Red’ would do as well. ‘Winter Gold’ is actually pale tangerine. They are planted in widely-separated locations, since together they would create a horrendous clash of color–or a dissonant duet. As solo performers they are unexcelled for dramatic color. (Once seen, ‘Winter Red’ in snow is never to be forgotten.)

Close by our little colony is one of the best trees for suburban landscaping, albeit badly neglected. The southern hawthorn, Crateagus viridis ‘Winter King’, first attracts admiration for its abundant crop of dark red berries, but then attention switches to the  handsome silvery bark. Our specimen, now about 12’ high will eventually double in size, remaining in scale. The native southern hawthorn is a fine candidate as an alternate to the much overplanted Bradford pear. Not only does it lack the pear’s disadvantageous branching pattern that makes it highly liable to damage from wind or ice; it also sports lovely fall color, in shades of purple and gold. As  the tree passes its juvenile stage, the smooth, silvery bark changes by thickening and beginning to exfoliate almost as beautifully as Lagerstroemia fauriei, the Japanese crape myrtle.

This hawthorn is of course a late spring bloomer, with white,  nondescript flowers. February’s far more interesting flowering comes from several of our collection of witch hazels or Hamamelis. There are fall blooming witch hazels, but many hybrids of the Chinese species H. mollis, known collectively as H. x intermedia, bloom between December and March, depending on the kind. One of the loveliest of these, ‘Jelena’, is a fragrant January and February bloomer that covers itself with wispy clusters of coppery orange. It grows just southwest of the arboretum’s Red Shed- a fine advertisement to passersby of the virtues of its genus. (Meanwhile, other witch hazels flower simultaneously with ‘Jelena’, but in more secluded locations. One of the finest of these is the bright yellow Hamamelis mollis ‘Wisley Supreme’, which is frequently mistaken for a forsythia that has jumped the gun by a month.)

Close neighbors of ‘Jelena’ are two of the newest arboretum acquisitions, both acquired last summer after a search of several years–Prunus mume ‘Bridal Veil‘ and Lonicera x purpusii ‘Winter Beauty’. ‘Bridal Veil’ is just one of the arboretum’s collection of cultivars in this remarkable genus, which is widely prized in Japan but thus far too seldom known or planted in North America.Distinguished by early bloom and delightful fragrance, the Japanese apricot bears single or double flowers of white, pink or red. Look for the honeybees on any Japanese apricot in January!

‘Bridal Veil’ is flowering profusely for us, as a juvenile plant nowhere near its ultimate size of roughly fifteen feet high and wide. Of whatever size, it is a great beauty.

Not so the our shrubby honeysuckle. Visually it will never live up to the name ‘Winter Beauty’. It is a scruffy little shrub, whose cream-colored flowers are scarcely visible from three or four feet away. But no matter, for these modest little flowers are among the most extravagantly and exquisitely perfumed plants of the garden. A twig with a three or four stray blooms can fill a room with a scent comparable to the perfume ‘Joy’—a scent that makes this shrub a must-have.

I’ve saved for last one of my favorite of all shrubs, but one I never heard of until around 2007, when I spotted one in the greenhouse of a wholesale nursery, the paper plant or Edgeworthia chrysantha. When I saw it, it was February, and the plant was gaunt and skeletal, but adorned with silvery clusters of tubular blossoms just beginning to show yellow–but so strongly and sweetly scented their perfume carried far in the still greenhouse air. Edgeworthias  look tender, but  have proved hardy. They are beautiful in every season, including summer, for their attractive blue-green, tropical-looking foliage.

By Allen Lacy