Purple loosestrife, Lythrum salicaria
Randy Westbrooks, U.S. Geological Survey, Bugwood.org
Invasive plant species threaten natural areas, and can invade your garden. Landscape plants that seed freely, like privet, can cause extra work for gardeners. Seedlings must be weeded out before they take over and displace plants which you painstakingly planted in your garden. Plants such as wisteria can spread quickly from your garden onto other people's property, decreasing both their enjoyment of their property and their enjoyment of you as a neighbor. Even plants which seem manageable in your garden may be spreading seeds into natural areas. The fruits on many plants, such as nandina and coral ardisia, are eaten and spread by birds, causing infestations many miles away.
Japanese beetles have a total host range of more than 400 species. Some of these hosts include roses, crepe myrtles and Japanese maples. Japanese beetles skeletonize leaf tissue (eat all leaf tissue between the veins and leave the veins behind). Adults attack flower buds and fruits, while grubs are considered the number one pest of turf and lawns. Japanese beetle infestations can greatly reduce the ability for your garden plants to grow and flourish. Gardeners in the United States spend an average of $460 million a year to control Japanese beetles in their gardens.
Japanese beetle, Popillia japonica
Clemson University, USDA Cooperative Extension,
Slide Series, Bugwood.org
Dogwood anthracnose, Discula destructiva
Robert L. Anderson, USDA Forest Service, Bugwood.org
There are also many invasive species you cannot see that affect your garden. Many invasive pathogens, such as dogwood anthracnose, oak wilt, mimosa wilt and Dutch elm disease can make plants unsightly and potentially kill them. Americans spend $2 billion each year controlling unwanted plant pathogens in lawns, gardens and golf courses.
What can gardeners do to help prevent the spread of invasive species?
- Go native! There are a wide variety of beautiful, easy to care for native plants available. Look for an alternative plant list for your state/region. The butterflies and other pollinators will love it!
- Never use invasive species in your landscaping.
- Remove invasive plants from your garden.
- Until you are able to rid your garden of invasive plants, be responsible and remember to remove and destroy seed heads before they can be spread. Also, never propagate invasives or share cuttings from invasives with other gardeners. Talk to other gardeners about invasives and how you plan to help in the fight against them.
- If you are worried that your garden will lose its luster after removing invasives, talk to your local native plant society or exotic pest plant council. These organizations will be able to suggest suitable native replacements.
- Before choosing a native plant alternative, first think about the characteristics of the invasive plant you are replacing. For example, if you like the showy fruits of autumn olive, try replacing it with American bittersweet. If you like Japanese wisteria for its vining habit and fragrant flowers, consider replacing it with American wisteria. If you like purple loosestrife for its vibrant magenta flowers, plant fireweed or purple coneflower instead.
Wavyleaf purple coneflower, Echinacea simulata
James Henderson, Golden Delight Honey, Bugwood.org
American bittersweet fruit, Celastrus scandens
Chris Evans, Illinois Wildlife Action Plan, Bugwood.org
Fireweed, Chamerion angustifolium
Joy Viola, Northeastern University, Bugwood.org
American wisteria, Wisteria frutescens
Gena Todia, Wetland Resources Environmental Consulting, Bugwood.org
American wisteria, Wisteria frutescens
Gena Todia, Wetland Resources Environmental Consulting, Bugwood.org