Know How to Spot Invasive Plants in the Landscape: Multiflora Rose & Garlic Mustard (2021 No. 10)

Home » Conservation Commission Notes 2021 » Know How to Spot Invasive Plants in the Landscape: Multiflora Rose & Garlic Mustard (2021 No. 10)

How does a plant earn the label ‘invasive’? According to the Ecological Landscape Alliance, invasive plants disrupt ecosystems by overtaking native plants, potentially limiting or eliminating food sources for pollinators and animals. Invasive plants can also alter soil chemistry, making it more difficult for native plant species to flourish.

Multiflora rose is a large perennial shrub that forms dense stands of impenetrable thickets that can grow up to 10 ft tall, displacing native vegetation. It can also grow as a climbing vine reaching heights of 25-30 feet, and forming large clusters of fragrant white or pink flowers that bloom June to July. Like other roses, it forms small red pulpy fruits called hips, which may be eaten by birds. It can be distinguished from native roses by its long arching stems and numerous small white flowers or hips depending on the season.

Multiflora rose is highly aggressive and colonizes old fields, pastures, roadsides, open woodlands, and forest edge habitats. It is most productive in sunny areas with well-drained soils. Multiflora rose is used for cover during all times of year by cottontail rabbits, white-tailed deer, pheasants, and mice, and it is a preferred nesting site species for gray catbirds. View photos of multi-flora rose.

Garlic mustard generally has a single flowering stem and emerges early in the spring in our area. It is identified by crushing the stems which releases the scent of garlic, hence its name. The flowers are white with 4-petals and seeds are produced beginning in May. Each seed pod contains between 12-19 seeds, and the number of pods per plant can vary greatly from 1 to more than 200. Seeds remain viable for up to 6 years,

Garlic mustard can have a wide range of negative impacts to both the environment and to wildlife. When their populations grow unchecked, they can outcompete native species by robbing them of light, nutrients and soil moisture. Their rooting systems and decaying leaf litter release chemicals into the soil, which inhibit the germination and growth of native plants. Garlic mustard can also negatively affect soil fungi essential for nutrient uptake by our native hardwoods. In addition, Garlic mustard has a toxic effect on the development of butterfly eggs when laid on the foliage or stems. View photos of garlic mustard.