September is a fine time to plant trees and shrubs and to divide perennials, according to Doris Taylor, Plant Information Specialist at The Morton Arboretum’s Plant Clinic.
“It’s cooler now and the soil is not as dry as in July, but there’s still plenty of time for plants to get established before the ground freezes,” she says.
The earlier you plant, the more time a tree, shrub or perennial will have to establish its root system before winter. Planting in autumn is all about giving the roots a good home in the soil so they get a solid start next spring, Taylor says. You will need to water the new plant regularly until the ground freezes and all season for the next year or two.
For detailed instructions on how to plant a tree or shrub, watch a how-to video.
If you’re looking for reliable shrubs to plant this fall in a Chicago-area landscape, consider selections from the Chicagoland Grows® Plant Introduction Program, which selects, tests, and releases plants that are excellently suited to use in home landscapes in our climate and soils. The program is a partnership between The Morton Arboretum, the Chicago Botanic Garden and the Ornamental Growers Association of Northern Illinois.
Here are five shrubs from Chicagoland Grows® that might be fine additions to your landscape. Ask for these cultivars at your local garden center or nursery. For other shrub suggestions that will suit the conditions of your site, consult the Plant Clinic or see the Arboretum’s Tree and Plant Finder.
Prairie Flame™ shining sumac (Rhus copallina var. latifolia ‘Morton’): The shiny green summer leaves turn a spectacular flaming red in fall, and there are lovely creamy-white blooms in July. This more compact cultivar was selected by the Arboretum from a native plant growing near the Indiana border. It needs full sun and is very tolerant of drought, although it can handle a wide range of soil conditions. It spreads by suckering and will reach seven feet high and 10 feet wide in 15 years.
Iroquois Beauty™ black chokeberry (Aronia melanocarpa ‘Morton’): A relatively compact cultivar of a native plant, this black chokeberry has showy spring clusters of small white flowers in mid-May. The black summer fruit is attractive to birds and the handsome green foliage turns orange to deep red in fall. This shrub was selected by The Morton Arboretum from seed collected in Kane County. It’s an adaptable plant that can handle full sun to part shade and wet to dry soil. Over ten years, it will grow only three feet high with a five-foot spread.
Northern Burgundy® arrowwood viburnum (Viburnum dentatum ‘Morton’): Beautiful red to burgundy fall color is the selling point for this selection of a native plant, although it also has creamy white flowers in June, followed by ornamental clusters of blue-black fruit in early fall. It’s a large shrub, growing eight to 10 feet high and wide, and very adaptable, growing in full sun to part shade and in soils from wet to dry.
Northern Charm™ boxwood (Buxus ‘Wilson’): This hardy evergreen shrub works well for formal hedges or as a specimen in the garden. Its small semi-glossy leaves are an attractive emerald green that takes on a bluish cast in summer and turns a darker green winter. It’s best in filtered sun to part shade, and grows three to four feet high and up to five feet wide in 15 years.
Scarlet Beauty Virginia sweetspire (Itea virginica ‘Morton’): This compact shrub has plenty of whimsical dangling white flowers in early summer, when few other shrubs are in bloom. The lightly fragrant blooms are attractive to butterflies and other insects. The fall color ranges from orange through red to purple. Sweetspire is native to the Southeast, but this cultivar was selected from a fully hardy shrub that had thrived at the Arboretum since the 1950s. It does best in partial shade in moist, somewhat acid soil, although it can tolerate more alkaline soil. Expect it to grow about three to four feet high and wide in five years, although it will slowly expand through suckers.