Myths and Facts
MYTH #1: Invasive plants aren’t really a concern in the Midwest. They’re more of a problem in places like California and Florida.
FACT: While invasive plants may have received more attention and publicity in other parts of the country, invasive plants are just as big a problem here as they are in other regions. It is estimated that 18% of the plants in national parks in the Midwest are non-native species, many of which are highly invasive. The percentage of invasive plants is even higher in areas with greater disturbance from human activity, such as roadsides or pastures.
MYTH #2: Species move around and expand their ranges naturally. When people introduce a new species, it’s no different than the natural process of species movement.
FACT: People are moving far more species at a much faster rate than any natural colonization or range expansion. By bombarding our ecosystems with many new, aggressive species over a short time span, we are exposing them to conditions that would never occur without human intervention.
MYTH #3: All non-native species are bad.
FACT: Many non-native species do not cause problems in the areas where they are introduced and can be important for agriculture, horticulture, medicine, or other uses. The species of concern are those that become invasive, taking over native ecosystems and crowding out native species. It is often difficult to know in advance if a new species that is introduced will become invasive, so great caution should be used when importing or planting new species.
MYTH #4: I live in an urban area, so it doesn’t matter if I plant invasive species. They won’t be able to spread to natural areas from my yard.
FACT: Even if you don’t live near a natural area, your yard could be a source of invasive plants. Seeds of invasive plants can be carried in many ways—by birds eating fruits and depositing the seeds elsewhere, by water carrying seeds from your yard into sewers that lead to rivers or streams, or by car tires or shoe treads when you travel to parks, nature preserves, or recreational areas. The best way to prevent the spread of invasive plants is to not plant them in the first place.
MYTH #5: Cutting, hand-pulling, or mowing are the best ways to control invasive plants.
FACT: This is true in some instances. Small infestations of some species, such as garlic mustard, can be removed by hand-pulling. However, hand-pulling for large infestations leaves large patches of disturbed soil, and often seeds from the seed bank will germinate and re-colonize areas where garlic mustard has been removed. Properly timed cutting or mowing can also control some species, however, perennials such as Canada thistle should not be cut or pulled. Removing only part of the plant will only stimulate growth and produce more plants. Combining cutting with herbicides can be an effective method of treatment for many species.
MYTH #6: Biological control methods such as insects are the answer to invasive plant problems.
FACT: There is no one miracle fix for controlling invasive plants. Relying on a single control method is unlikely to be successful. The best approach is an integrated management plan tailored to specific sites and species that includes a combination methods appropriate to the situation, such as chemical control (herbicides), biological control (insects or pathogens), mechanical control (pulling or cutting), and prescribed burning.
MYTH #7: Biological control is a bad idea, because it involves the release of non-native insects or pathogens that could damage native plants in addition to the targeted invasive plants.
FACT: In years past, some biological control efforts were poorly planned, and as a result, there were some unintended negative consequences of releasing non-native organisms to control invasive plants. These days, however, biological control agents are highly regulated and extensively tested prior to their release in the U.S. Scientists conduct careful experiments in quarantine facilities to determine whether potential biological control agents have the ability to feed or develop on plants native to the U.S. If the potential biological control agent does not feed on native plants and shows itself to be specific to the target invasive plant species, it can then be approved for release. Biological control agents should always be carefully monitored after their release to watch for any unanticipated effects on native ecosystems.