A Splash of Color Appeared (and it's an invasive species) "Dame's Rocket"

 I noticed some tall purplish flowers behind my fence this year.  I wondered where they came from.  We may have had a few before but not like this.  Back in 2019, I did grab flowers similar to this from my mom's house and planted back there.  They didn't do very well.  I knew they were not phlox because they were taller.  Turns out they are called Dame's Rocket.

Fast-forward to this year and I likely kicked this off OR the seeds just blew in (read below for how prolific they are).

(from the web)

Dame’s rocket, Hesperis matronalis, is a fragrant, edible member of the Brassicaceae family of plants, which includes arugula, broccoli, and mustard. Native to Europe and Asia, it was originally brought to the United States as an ornamental plant.

As with many introduced varieties, its seed spread beyond garden borders and naturalized in surrounding woodlands and meadows. Unfortunately, it is an aggressive grower that competes with native plants, threatening natural ecosystems with its spread.

Classified as invasive in many regions, H. matronalis is especially vigorous in the Midwest and Northeast regions of the US.

Many plants can become invasive under ideal growing conditions. Be aware that if you allow seeds to disperse from this plant, it will spread readily under ideal growing conditions.

It looks like a native garden phlox, Phlox paniculata, but to be certain, count the petals.

H. matronalis has four, but phlox varieties have five. In addition, dame’s rocket has leaves that alternate along the stem while phlox leaves are arranged opposite each other.

Dame’s rocket is a biennial, which means it blooms in the second year of growth. After pollination and seed formation, it is a vigorous self-sower.  It is believed that this plant was introduced to North America in the 1600s, so it’s had plenty of time to make itself at home.

The flowers may be magenta, pink, purple, or white. In addition to botanical species, which has one row of petals, there are cultivars with two.  Bloom times range from May to August.

H. matronalis is a fairly tall plant with stems that range from one to three feet, or sometimes four feet in height.

Deer don’t bother with it. That figures!