Common Tansy: A Persistent Invasive Plant
Identification
Common tansy (Tanacetum vulgare) is a highly invasive perennial plant that is easily recognizable by its distinctive features. It boasts dark green, fern-like foliage with golden, button-like flower clusters that bloom atop stems reaching up to 5 feet in height. This aromatic plant was once prized for its medicinal properties but has since become a major threat to North American ecosystems.
Invasiveness
Common tansy is a prolific seed producer and a vigorous spreader via its rhizomatous roots. It forms dense stands that can quickly overtake native vegetation, reducing biodiversity and degrading wildlife habitat. The plant’s toxicity to humans, cows, and horses further exacerbates its impact on the environment.
Removal
If common tansy has established itself on your property, it is crucial to eliminate it promptly. Individual plants or small patches can be removed manually by digging them out with a shovel, ensuring the removal of all roots. However, this method is only effective for small infestations.
For larger infestations, a broad-spectrum herbicide may be necessary. Target the plants to be removed and follow the instructions carefully to minimize environmental impact. Mowing before applying herbicide can weaken the plants and reduce the amount of herbicide required.
Prevention
To prevent common tansy from spreading, it is essential to remove plants before they set seed. This can be done by cutting or pulling them out before or during the flowering period in the summer. If removal occurs after seed heads have developed, new plants may germinate the following year.
Distinguishing Common Tansy from Tansy Ragwort
Common tansy can be differentiated from tansy ragwort (Senecio jacobea) by its unique flower structure. While common tansy has yellow, button-like blooms, tansy ragwort has daisy-like flowers with 13 ray petals and yellow centers. Both plants are considered noxious invasive weeds.
Frequently Asked Questions
- What are the uses of tansy flower?
Traditionally, tansy flower was used in various medicinal applications. However, scientific evidence supporting its medicinal properties is limited, and it is primarily considered toxic.
- Should I plant tansy to keep mosquitoes away?
Research suggests that distilled oil from common tansy can effectively repel mosquitoes. However, it is important to note that the plant itself may pose a health risk to humans and animals.
- What are tansy flowers symbolic of?
Tansy is associated with immortality, protection, health, and resistance. The word “tansy” originates from the Greek word “athanasia,” which means immortality.
- What is the best time of year to remove common tansy?
The optimal time to remove common tansy is before or during the flowering period in the summer, before it sets seed.
- What are the natural enemies of common tansy?
Currently, there are no known natural enemies that effectively control common tansy.