In many parts of the country, the winter garden doesn’t offer much that’s ornamental. Interesting bark, dried seedheads or hydrangea blooms and ornamental grasses certainly help, but for structure and permanence, nothing beats evergreen shrubs. And for that special touch of interest, broadleaf evergreens stand out among the sleeping plants to offer cover and color during the long cold months.
We’ve highlighted a few here. What’s your favorite?
Although it’s closely related to the iconic, spiny-leaved holly we so often associate with Christmas, Ilex glabra offers a different look with its smooth-margined, fl at, elliptic (or ovate) foliage. Alternate leaves — about 1 to 2 inches long — are dark green and glossy and may have a couple of small notches on either side of the apex, creating a subtle toothed effect. Color remains reliably rich throughout the season, but depending on the cultivar, in colder months the foliage may develop a purplish tone.
Very small, rather insignifi cant white fl owers appear in late spring or early summer. If there’s a local pollinator, these develop into dramatic, black, berrylike fruits about the size of peas that emerge in early fall and persist throughout the winter — unless they’re consumed by birds.
Inkberry is a slow-growing shrub that reaches about 3 to 4 feet tall with a spread up to about 6 to 8 feet in full sun and part shade. It can tolerate wet feet; in fact, it prefers very moist soil, but otherwise is a low-maintenance selection.
Hardy in zones 4 to 9.
Mountain laurel’s distinctive clusters of cup-shaped fl owers may be gone in winter, but the sturdy foliage remains even in the coldest months. Alternate, elliptic, 5-inchlong leaves are leathery and glossy, and tend to resemble those of rhodies. They appear dark green above with a yellow cast beneath, and remain so throughout the year. If planted in full sun, foliage may take on an overall yellow-green appearance.
This multistemmed, somewhat twisting and gnarled shrub reaches from 5 to 15 feet tall with an equivalent spread; if grown in southern Appalachia, however, it can develop into a 30-foot-tall tree. If the plant is pruned shortly after spring bloom, a more compact habit can be maintained.
The most outstanding feature of Kalmia is its outstanding display of spring fl owers, which appear in terminal clusters and virtually cover the plant in late spring and early summer. But this broadleaf evergreen serves the winter landscape well.
Hardy in zones 4 to 9.
(holly-leaved barberry, Oregon grape holly)
There are several species of evergreen Mahonia, including M. bealei, M. repens, M. trifoliolata and M. japonica, among others, but one of the most popular and most reliable is M. aquifolium. It’s an easy-to-grow shrub that’s native to the Pacifi c Northwest, featuring a spreading to upright habit; its normal height is about 3 to 6 feet with a similar spread, but it can be trained to grow a bit taller in shade.
Oregon grape holly offers impressive ornamental characteristics in all seasons, from its bronze-red foliage and prolifi c racemes of bright yellow fl owers in spring through shiny, sturdy, deep green foliage in summer. In fall, the foliage turns somewhat purplish, then deepens in winter to a rich burgundy with bronze overtones in winter.
Bright blue, grapelike berries follow the spring bloom; these ripen to a blue-black by the end of summer into early fall.
Hardy in zones 5 to 8 (9).
Pick one. Rhodies are the quintessential shrub of the Southern mountains — stroll along the Appalachian trail any spring and you’ll be bowled over by the intense blooms. But these evergreen beauties can be found — and can perform well — in colder regions across the country. The PJM type, developed in New England by the Mezitts of Weston Nurseries, is particularly suited to challenging climes. Their smaller cousins, the azaleas, also boast many varieties with evergreen foliage, but we’ll turn, for now, to rhodies.
Desiring part to full shade, rhododendrons generally reach 3 to 6 feet tall by about 3 to 6 or 7 feet wide in a rounded habit. An astonishing array of cultivars offers larger, smaller, shorter, stockier, rangier forms, but this is a good average. Rhodies like good drainage but should not be allowed to dry out.
The distinctive fl oral display, bursting in clusters in a wide variety of colors, appears in early spring. Foliage is elliptic, and depending on the selection, can range from about 2.5 to 3 inches to a bit longer; it is leathery and dark green, taking on a regal purple tone in winter.
Generally hardy in zones 4 to 8.
PROTECTING BROADLEAF SHRUBS IN WINTER
Customers and clients are pushing the limits of hardiness zones, testing the ability of cold-hardy plants to survive just a bit beyond, just one zone colder than that for which they’ve been trialed. For that, they need a bit of protection. And the shrubs we’ve highlighted here all are reliably hardy in their designated zones, but in these times of record temperature swings, they may also need some help.
It’s not just dips on the Fahrenheit scale that can threaten broadleaved evergreens, however. Heavy, wet, dense snowfall may snap branches, and intense winter sun and whipping winds can challenge the hardiest of shrubs, dessicating and burning the foliage.
To help keep those hardy evergreen shrubs strong and healthy throughout the colder months, there are a few easy-to-follow recommendations.
- Provide suffi cient water in fall, before the fi rst hard frost arrives and the plants go dormant. This conserves water and prevents the frozen ground from cutting off their supply of moisture.
- If plants are subject to potentially damaging winds, a temporary screen can be erected. It’s not the best look, but if the shrubs haven’t been properly sited, a shield can work. Better yet? Plant them away from the threat of frigid winds. Siting in a protected spot is particularly benefi cial for rhodies.
- Antidessicants applied to both sides of the foliage can help prevent loss of water.
SCALLYWAG HOLLY AN INTERNATIONAL WINNER
Monrovia’s Scallywag™ holly (Ilex × meserveae ‘Monnieves’ PP 21,941), a sport of Little Rascal® holly, received the prize for IPM Novelty 2018 in the shrubs category at IPM Essen. The show, held in Essen, Germany, is the world’s leading trade fair for horticulture.
According to Jonathan Pedersen, Monrovia’s vice president of business development, “Scallywag™ holly is an important plant in the landscape trade and with home gardeners for its improved disease resistance, lowmaintenance needs, and because it grows more upright, dense and compact than other Ilex cultivars. This makes it a problem solver in small gardens needing a solid, evergreen structural shrub. And, it looks great year-round with shiny dark-green foliage that takes on a purple-burgundy hue in the fall and winter.
This compact shrub reaches 4 feet tall by 3 feet wide and features a dense, rounded form with an upright habit. White flowers appear in spring, but this male hybridizer does not produce berries.
Scallywag was discovered at the company’s Dayton, Oregon, nursery.