Does your landscape need a boost from new trees, shrubs or groundcovers? Arbor Day is coming next month (April 30), and we’re beginning to enter a great time to plant woody plants. Let me encourage you to do a little homework before you go to your favorite local plant retailer to make your purchases.
Most trees are best planted in the spring or fall, but some tree species really prefer spring planting, such as oak, sour gum and redbud.
Besides researching the right plant for the right place in your landscape, another important thing to consider is whether the plant is invasive or not. Several consumer favorites in past decades have been found to be invasive in natural ecosystems, displacing native species.
In a 2015 Purdue Extension publication entitled, “Alternative Options for Invasive Landscape Plants,” Purdue experts urged the green industry to transition to plants that provide an alternative to some of the most notorious and damaging invasive plants, including Norway maple, black alder, amur cork tree, callery pear, and wintercreeper (a woody groundcover).
The unique nature of the information in the publication is that it includes optional plants that are both native and non-native to Indiana; included non-native species were ones that cause no known problems for natural ecosystems. The species listed were considered by the authors to be viable retail alternatives. The publication was reviewed by representatives from Purdue University, Indiana Nursery and Landscape Association, Indiana Arborist Association, the Nature Conservancy of Indiana, Indiana Department of Natural Resources, and the Indiana Native Plant Society.
For the general public, the publication may give additional options for you to consider as you plan your landscape plantings.
One of those “notorious” invasive plants, callery pear, can produce abundant fruit that are widely distributed by birds. The development of additional cultivars beyond the original “Bradford pear” has allowed these trees to cross-pollinate and produce fruit with viable seeds. In natural areas, the result can be thickets of callery pear that do not allow regeneration of desirable native species, such as oak and hickory. While it produces beautiful spring flowers in its symmetrical crown in the spring, this is accompanied by the smell of rotting fish. Bradford pear has a weak branching pattern that can cause numerous limbs to break after storms that have high winds or cause ice accumulation. Callery pear cultivars can also produce thorns.
Although it’s not covered in the aforementioned publication, winged burning bush (Euonymus alatus) is an example of a popular shrub that is causing major headaches in natural areas. The species is highlighted in a separate publication, again authored by Purdue experts, entitled, “Invasive Plant Series: Winged Burning Bush.”
Find the above-mentioned Purdue Extension publications at: www.edustore.purdue.edu.