Plants that have become invasive problems tend to have certain characteristics in common. High-volume use in landscaping and a long period of time since introduction tend to increase a plant's invasive potential. Invasive plants also often exhibit some or all of the following characteristics:
- Rapid growth allows shading out of native plants.
- Short life cycle: go from seed to producing seed very rapidly — sometimes within a few weeks!
- Deep root system.
- Prolific flowering.
- Ability to grow in a wide range of habitats.
- High number of seeds produced.
- Long seed dormancy and staggered germination.
- Efficient method of seed dispersal.
- Ability to reproduce sexually (by seed) and asexually (vegetative reproduction) by sending out aboveground or belowground “runners” (stolons and rhizomes), or by growing new plants from fragments of the original plant.
- If reproducing sexually, they are attractive to insects, birds, bats, or other pollinators found in the new environment.
- Often, the timing of the invasive plants' growth and reproduction does not coincide with the growth habits of native plants; this can provide an advantage of resource availability for the invasive plant and allow it to get a head start.
- Allelopathic properties, which is the release of chemicals into the surrounding soil that prohibit the growth of other plants.
- Resistant to grazing. For example, they may have thorns, toxins, or a high silica content making it difficult or unpalatable to wildlife.
Unfortunately, some of these characteristics are often desirable in ornamental and landscape plants. It is important to keep this potential in mind when considering other imported plants for your landscaping needs. We can also help our public officials to be well educated about the potential invasiveness of new imports so that they can maintain diligence when determining which plants to allow into the country.