Invasive plants are sold in nurseries, through catalogs and online. The fact that a plant is readily available commercially does not mean that the plant is a smart choice for your landscape. Beyond invasive, some plants are simply inappropriate for practical reasons.
Trees are long-term plants, an asset that matures in your landscape. They are not so easily disposable as an annual that exhausts itself in one season, or a perennial that you can transplant to a more suitable location.
If you buy a tree as a fast fix for shade, privacy or landscape interest you may get more than you bargained for. Here are some well-known landscape trees, invasive and troublesome, that you should not plant in your yard.
Leyland cypress has been the go-to plant for homeowners who want to grow a quick privacy screen. Unfortunately, the trees are now beset by a number of problems.
Leyland cypress is increasingly susceptible to disease and insect problems. They suffer from Seiridium canker, Botryosphaeria dieback, Passalora needle blight and root rot, as well as infestation with bagworms, spider mites and scales.
The trees are grow fast; consequently, they don’t develop good root support. The taller they grow the more easily they uproot in a storm. In addition, dry twigs in the center of trees make them a fire hazard. Consider Green Giant arborvitae (Thuja), magnolias and hollies instead.
Russian Olive (Elaeagnus agustafolia), Thorny Olive (E. pungens) and Autumn Olive (E. umbellata) were brought to the U.S. from China and Japan as ornamentals in the 19th century. They have since escaped cultivation to become invasive. They make fast hedges but these landscape plants continue to invade the natural environment.
Elaeagnus species develop abundant fruit which is eaten and the seeds dispersed by birds and small animals. The scattered seeds germinate and grow to crowd out more desirable native plants in the natural environment.
Bradford pear, a cultivar of the callery pear, another China import, is a fast grower that develops with weak brittle wood and narrow branching angles. That causes trees to easily split and crack with wind and ice. Moreover, the trees are invasive.
Birds eat the trees’ fruit and disperse the seeds in the wild. Bradford pear and other callery pear cultivars readily cross-pollinate and revert to their original invasive character, colonizing and forming thickets. Be aware also that Bradford pPears’ spring flowers may be pretty but they stink. Consider planting a redbud or Yoshino cherry instead.
Weeping willows are fast-growing trees. As a result they also have weak brittle wood, prone to cracking. The trees develop shallow troublesome roots that spread from the tree in every direction, well beyond its canopy. When planted in a yard roots can damage patios, sidewalks and driveways. Septic systems and irrigation lines are in harm’s way, too. If you want the look of a weeping tree investigate river birch and weeping cherry.
Silver maple is the fastest growing of American maples. It grows into a tall shade tree, but its soft weak wood is prone to cracking in storms. The tree is vulnerable to disease and susceptible to mites, aphids and scale. Its vigorous roots upheave driveways and sidewalks. It is costly to have a tree removed. Even a cheap silver maple is not worth the bargain.
Mimosa is another fast- growing tree with weak brittle wood that is prone to breaking. Its attractive showy flowers produce a large number of seedpods full with seeds that readily germinate, thereby producing seedlings that pop up in lawns, gutters and gardens. The seeds are easily transported by water which deposits them in new locations to germinate.
In its own yard, mimosa also sprouts from its roots, especially when they are damaged or the tree is cut back. If you want a flowering tree, consider crape myrtle.
Note about crape myrtles: They are available in different sizes: very dwarf, 1 to 3 feet; dwarf, 3 to 6 feet; semi-dwarf, 5 to 12 feet; small tree 10 to 20 feet; and tree, 20+ feet. When you buy a crape myrtle be sure to match its mature size to its intended site. There is no justifiable reason to top a crape myrtle.
Reach DEBBIE MENCHEK, a Clemson Master Gardener, at firstname.lastname@example.org.