White mulberry is an invasive tree that homeowners and land management need to try to control. It reseeds easily, is spread by birds, and has actually bullied the native red mulberry (Morus rubra) right out of our landscapes. My father always called the white mulberry a “junk” tree, and he was right.
Barberry is an invasive shrub that has been overused in design, overplanted by landscapers, and is still sold in many garden centers to homeowners. Seeds are spread by birds, but do you know these seeds can live for up to 10 years in the soil? Chokeberry (Aronia arbutifolia or melanocarpa), silky dogwood (Cornus amomum), and arrowwood viburnum (Viburnum dentatum) are wonderful native alternatives.
Oriental bittersweet is a non-native highly invasive vine that girdles trees and shades out light and nutrients to trees. Seeds are spread by birds, so please do not even use it for decoration. There is a native bittersweet vine that has no yellow when the orange berry sets, and that is a good plant.
English ivy is an invasive vine that not only girdles our trees and but also spreads disease to our trees. Why is English ivy still sold in some of our garden centers? Flowering native vine alternatives are American wisteria (Wisteria frutescens) or flowering passion vine (Passiflora incarnate)
These are just a few examples of invasive plants. These plants act as a seed bank, and we should not plant them in our gardens. They should not be sold in garden centers and should not be used in garden design. This will only change if we, as educated consumers, speak up and request native alternatives that provide safe plant communities to fulfill the life cycle of wildlife, providing proper habitat of cover, food, and a place to raise their young.
A good starting reference book is Plant Invaders of the Mid-Atlantic Natural Areas. Copies are available in the Arboretum gift shop. Also pick up Native Plants for Wildlife Habitat and Conservation Landscaping if you do not already have it.
By Robyn Affron
Certified Professional Horticulturist