Did you note a lack of vertical structure in your landscape this past winter? Spot yawning holes in your borders? See too much of your neighbor’s compost heap? Behold bare stretches of foundation and fencing?
If your landscape sparked as much interest as flat farmland, consider enlivening it with shrubs. Whether deciduous or evergreen, shrubs make for focal points, privacy screens, foundation camouflage and perennial companions. And early spring is prime time to plant them.
Before you buy that holly, forsythia, or yew, though, think about its placement and its purpose, says Tim Boland, curator of horticulture at The Morton Arboretum in Lisle: “When people are adding shrubs, they need to consider what they want the shrubs to do. Are they going to plant them in mass for screening, use them to define a space or interplant them in a mixed border? They need to think of the ultimate height and width of the plant, its growth rate and its seasonality, noting when it blooms and if it offers fall color or winter interest … and how it combines seasonally with neighboring plants.”
Sara Rexroat, horticulturist at Jayson Home and Garden in Chicago, says shrub shoppers should know the exact dimensions of their shrub-planting sites and whether those sites are sunlit or shaded. Consider flowers, fragrance and form, and then pick plants that won’t outgrow their allotted space.
“There are more and more options to choose from–especially in the dwarf varieties, which are excellent choices for urban settings, small suburban lots and containers,” says Rexroat. “Choose interesting varieties that fit the site–ones that you can work with instead of fight against. If you only want it to get 3 feet tall, then choose a shrub that will only grow to that height, so you don’t have to keep cutting it back year after year.”
Large, medium and low
Boland says shrubs are generally sorted into large, intermediate and low-growing categories, with each classification fulfilling a different role in the landscape.
Reaching 8 feet or more, large deciduous shrubs, such as common lilacs, arrowwood viburnums (Viburnum dentatum) and winterberry supply prime nesting spots for birds, make dramatic backdrops for shorter plants and are often massed for screens. Filling a similar role are intermediate-sized evergreens, from 6 to 20 feet in height, such as varieties of Sawara cypress, Chinese juniper and arborvitae.Between 5 and 8 feet in height, intermediate deciduous shrubs such as oakleaf hydrangea (Hydrangea quercifolia), American hazelnut (Corylus americana) and forsythia can enclose a garden room or anchor flower borders.
Low-growing evergreens (less than 4 feet tall) and deciduous shrubs (less than 5 feet tall) fill a similar niche. A few recommended by the arboretum include `Annabelle’ hydrangea, `Arthur Simmonds’ bluebeard (Caryopteris x clandonensis), `Goldflame’ Japanese spirea, `Old Gold’ Chinese juniper, `Rheingold’ arborvitae and `Procumbens’ creeping Norway spruce (Picea abies).
Low-growing shrubs are good choices for tucking into flower borders and for including in foundation beds, where they make naturally-shaped replacements for the squared-off clipped evergreens that once were fashionable, says Stan Davis, horticulturist and owner of Vintage Landscape Care in Dundee.
“The concept for today’s foundation plantings is to have more flowing beds, to curve the beds out away from the house, to play up the architecture of the home and not have shrubs that are all the same height,” notes Davis. “People should decide on whether they want the foundation bed to be formal or informal, and then they should extend the beds out and step the plantings down two or three times away from the house.”
In an informal foundation planting, a flowering crab or a pagoda dogwood might step down to a section featuring rugosa roses, Japanese kerria or viburnum. Lower levels of the bed design could include `Gro-low’ fragrant sumac (Rhus aromatica), dwarf conifers and boxwoods, with perennials and ground covers at their base.
Rexroat recommends including ornamental grasses, Russian sage, tree peonies and other perennials that hold their shapes and interest through the winter.
For formal foundation plantings, Davis advises using boxwoods such as `Chicagoland Green’ and `Green Mountain’; `Brownii,’ an upright Japanese yew, and Koreanspice viburnum (Viburnum carlesii), a very fragrant bloomer that makes a nice under-the-window addition. Foundation beds with a more carefree look might contain lilacs such as `Palibin’ and `Miss Kim,’ hydrangeas, spreading cotoneaster and St. John’s wort.
Shrubs everywhere
But shrubs aren’t just for hiding foundations–they are multifunctional plants, contributing dramatic silhouettes and structure throughout the landscape. “Don’t be afraid to put them out in the yard as a specimen or use them as the backbones of your flowerbeds,” says Rexroat. “Use ones that have four-season appeal, interesting branch structure, extreme variegation or weeping or contorted forms as focal points or specimen plants.
“Be open-minded to plants you haven’t seen before. You may be reaping the benefits–maybe a great flower show, maybe it will keep its leaves longer into fall–of an exemplary plant that brings new character to your gardens.”
Planting a new shrub
Shrubs are sold three ways: in pots they were grown in; with a burlap-wrapped ball of roots; or bare-root.
You will find container-grown shrubs at garden centers and balled-and-burlapped shrubs at nurseries from now until fall. Early in the season, you also may find bare-root plants. Careful planting is the biggest factor in a shrub’s success.
Bare-root shrubs: Dig a hole slightly wider and deeper than the roots. Form a mound of soil in the center of the hole and set in the plant, arranging its roots around the soil mound. Fill the hole halfway with soil. Lightly press the soil around the roots and water well. Finish filling the hole and water well.
Container-grown plants: Dig the hole to the same depth and 10 to 12 inches wider than the root ball. Center the plant in the hole. Fill the hole and water as for bare-root shrubs.
Balled-and-burlapped plants: Dig a hole as for container-grown plants. Center the shrub in the hole. Loosen the burlap and pull it gently away from the sides of the root ball, but leave it in the hole. Fill the hole and water.
After planting any shrub, create a shallow water-retaining depression around the trunk to capture water and direct it toward the plant’s roots. Spread an even layer of organic mulch over the planting area, keeping it a couple of inches away from the plant’s trunk. Don’t mound it up around the trunk.
— Ann Wilson.
Learn more about shrubs
To learn more about shrubs recommended for the Chicago area, tour public gardens, including the Chicago Botanic Garden Garden, 1000 Lake Cook Rd., Glencoe ($7.75 parking fee; call 847-835-5440) and The Morton Arboretum, Illinois Highway 53 and Interstate Highway 88, Lisle ($7 parking fee; call: 630-719-2400).
The arboretum sells brochures for $2 that include descriptions and cultivation information about each category of shrubs. The Chicago Botanic Garden’s Web site, www.chicagobotanic.org, features a comprehensive list of the best plantsfor Illinois, including shrubs.
A knowledgeable local source for dwarf evergreens is Rich’s Foxwillow Pines Nursery in Woodstock (815-338-7446; www.richsfoxwillowpines.com).
— Ann Wilson.
