Not So Fast: Fast-growing Trees Not Necessarily A Homeowner’s Best Choice
By Cathy Jean Maloney
The Morton Arboretum
“Is there such a thing as a bad tree?” So asks Kris Bachtell, Director of Collections and Facilities at The Morton Arboretum. It’s a fair question. In the right place, the right plant with the proper care can work well. Yet homeowners might think twice about planting some trees – and luckily there are good alternatives.
Take boxelder, for example. Even an arborphile like Bachtell is hard pressed to find many good things to say about boxelder. Commonly called a “weed tree,” boxelder grows quickly, but has very brittle, weak wood. The female tree also produces many “spinner” seeds, or samaras, which litter the ground with countless seedlings.
Quick growth and weak wood are common to many less desirable trees; that is, if you are looking for stability and longevity. Frequently, homeowners seeking “instant landscapes” might opt for the quickest growing tree, forgetting perhaps its short lifespan.
Another prolific and fast-growing tree, silver maple, also has shallow roots and brittle wood making it vulnerable in storms. Although Bachtell defends silver maple as a stalwart urban tree which thrives where none others may grow, he concedes that, given a choice, homeowners might be better off with something a little sturdier.
Bachtell lists a host of other maple trees that would substitute nicely for silver maple. Freeman maples are hybrids between the silver and red maple, retaining the latter’s brilliant fall color and strength along with the faster growth rate of the silver maple. Among the cultivars are Scarlet Sentinel, Autumn Fantasy® Autumn Blaze®, and ‘Marmo.’ ‘Marmo,’ developed through The Morton Arboretum, is seedless, has a medium to fast growth rate, and has better branch structure and strength than a silver maple. “These cultivars are more refined in growth, easier to train, have stronger wood and better natural structures, and those selections that fruit, produce smaller fruits,” Bachtell says.
Property owners should also find alternates for trees that are seriously threatened by exotic pests. Most arborists now advise against planting any type of ash tree because of the potential devastation from the Emerald ash borer. “It’s a big loss,” says Bachtell of the ash tree threat. “White ash has great fall color and green ash is as tough as they come.”
Instead, to obtain the height and scale of ash trees, Bachtell recommends disease-resistant elms, sycamores, oaks or honey-locusts. Elms such as Accolade™ or New Horizon are Asian hybrids that are very resistant to Dutch elm disease.
Of course we know that buckthorn is a most undesirable tree – and in fact it is illegal to sell it in Illinois. This highly invasive plant nonetheless sometimes finds its way as a volunteer onto a homeowner’s property. By the time it’s discovered, it has formed a thick privacy screen. Instead, Bachtell recommends a wide variety of trees or shrubs for quick growing hedges: varieties of cotoneaster, Chinese lilac, northern bayberry and arrowwood viburnum all make nice hedges.
Glad You Asked
Q. I just moved into a new subdivision and want to plant something that will grow quickly.
A. Unfortunately, the soil in new subdivisions is often quite poor and compacted due to construction. Your best bet is to improve the soil first by adding organic matter, and possibly berming areas to improve poor drainage. Then, be patient and plant hardy, disease-resistant trees such as the maples and elms mentioned above. If you need quick privacy or greenery, consider annual vines on trellises until your trees grow.
Q. Is the Bradford pear a good tree?
A. Bradford pears are ubiquitous in many suburbs because they grow fast and have a nice symmetrical shape and produce spring flowers. The narrow v-shaped junctures which render them susceptible to storm breakage can be avoided with careful pruning. This selection is also being considered by some professionals as a potentially invasive plant.
At The Arboretum
Get ready to see a championship that you likely have never seen before! In “Up A Tree,” professional arborists perform their version of an X-Tree-m sport in the professional tree-climbing championships. Free with Arboretum admission. June 7: 8:30 a.m. – 6 p.m.
Cathy Jean Maloney is a writer for the Morton Arboretum.