Spring has sprung! And like many other Americans, your attention may now turn to neglected yards. It's time to clean up, remove broken branches and perhaps replace plants lost to snow and ice this winter.
But be careful when choosing plants. You could unknowingly introduce nonnative invasive plants into your yard and surrounding environment. Often homeowners don't even know that a plant in their yard is an nonnative invasive species and can become a menace in the wild.
Plants are considered invasive if they spread out of control, dominate the local environment and crowd out native plants. Invasive plants grow fast and mature early in the season and reproduce profusely.
Invasive plants share a few common qualities that make them a threat to the natural areas: They spread aggressively by runners or rhizomes; produce large numbers of seed that survive to germinate; and disperse from the parent plant through a variety of avenues including wind, water, wildlife and people.
Nonnative invasive species are those that have been introduced into an environment in which they did not evolve, thus, there are no natural predators, parasites or other controls to keep these plants in check.
Native plants are generally recognized as those occurring on the continent prior to European settlement.
Not all nonnative species are a problem. Many of these plants have great economic value for agriculture, forestry, horticulture and other industries and pose little to no threat to our natural ecosystems. It is the invasive plants that pose a serious ecological threat.
Invasive plants are a problem because they are aggressive, outcompeting native plants for light, water and nutrients and eliminating entire native plant communities. They change the composition of the landscape. The ecological balance of plants, animals, soil, and water achieved over many thousands of years is destroyed.
As native plants are displaced, animal populations that rely on native plants for food and shelter also decline. When invasive plants take over wetlands, forests or meadows, the native plants and the habitats that local wildlife need are lost.
Invasive plants also affect the type of recreational activities in natural areas, including boating, bird watching, fishing and exploring. Some invasives become so thick that it is impossible to access waterways, forests and other areas.
According to the Plant Conservation Alliance's Alien Plant Working Group, about 1,050 plant species have been reported as being invasive in natural areas in the United States. This is roughly one-third of the nonnative plants species established and self-reproducing in the wild.
Estimates indicate that nonnative plants infest 4,600 new acres of federal land each day. Overall, invasive plants threaten every aspect of the North American environment including national wildlife refuges, national parks, recreation areas, wilderness areas, forests, wetlands and croplands.
Once established, invasive plants require enormous amounts of time, labor and money to control or eliminate. Invasive plants and animals cost the United States an estimated $120 billion each year in control and damages.
How you can help? Be careful when choosing plants. Become familiar with invasive plant species in your area and avoid planting them. Ask for native plant alternatives at your nursery. If you already have invasive plants on your property, consider removing them and replacing them with native species.
Kathy Reshetiloff is with the U.S. Fish and Wildlife's Chesapeake Bay Office in Annapolis.
To Learn More About Nonnative, Invasive Plants, contact, or visit these sources
- The National Park Service and U.S. Fish and Wildlife Service created a guide: "Plant Invaders of Mid-Atlantic Natural Areas." It describes common invasive plants and native alternatives to use in their place. To download a copy, visit www.nps.gov/plants/alien/pubs/midatlantic.
- Visit the Plant Conservation Alliance's Alien Plant Working Group website at www.nps.gov/plants/alien/ or the National Invasive Species information center at www.invasivespecieinfo.gov.
- Contact state native plant societies for information about native plant alternatives to invasive species.
- Contact a state university Cooperative Extension Service for advice on controlling invasive plant species.
Replace Invasives with Natural Beauties
Here are few troublesome species to avoid and native alternatives.
- Avoid purple loosestrife (Lythrum salicaria). Instead, plant blazing star (Liatris spicata), New York ironweed (Vernonia noveboracensis), obedient plant (Physostegia virginiana) and Joe Pye weed (Eupatorium dubium).
- Avoid common daylily (Hemerocallis fulva). Instead, plant wood lily (Lilium philadelphicum), Canada lily (Lilium canadense) and ox-eye sunflower (Heliopsis helianthoides).
- Avoid Chinese wisteria (Wisteria sinensis) and Japanese wisteria (Wisteria floribunda). Instead, plant: American wisteria (Wisteria fructescens), trumpet creeper (Campsis radicans) and trumpet honeysuckle (Lonicera sempervirens)
- Avoid English ivy (Hedera helix) and Japanese pachysandra (Pachysandra terminalis). Instead, plant alum root (Heuchera americana), white wood aster (Eurybia divaricata), foam flower (Tiarella cordifolia) and partridgeberry (Mitchella repens).
- Avoid winged burning bush (Euonymous alata) and Japanese barberry (Berberia thunbergii). Instead, plant red chokeberry (Aronia arbutifolia), Virginia sweetspire (Itea virginica) and highbush blueberry (Vaccinium corymbosum)
- Avoid tree of heaven (Ailanthus altissima). Instead, plant staghorn sumac (Rhus typhina), ash (Fraxinus pennsylvanica or americana) and black walnut (Juglans nigra).
- Avoid Bradford pear (Pyrus calleryana 'Bradford'). Instead, plant redbud (Cercis canadensis), serviceberry (Amelanchier canadensis), southern arrowwood (Viburnum dentatum) and flowering dogwood (Cornus florida).