Text & Photos: Maria Moore
It’s High Summer and the the cream color of Queen Anne’s Lace and the golden yellow of Goldenrod are a common sight along our country roads and fields. More and more, however, the bright lavender-purple color of Purple Loosestrife is present and then, imperceptibly, over the course of several years, the balance changes and the creams and golden yellows of native plants are gone, replaced by a sea of lavender-purple.
Over the last several years I have watched with a heavy heart as the Purple Loosestrife has steadily taken over some open fields between Torrington and Litchfield. It would only be a matter of time I knew before the same scene would be repeated in New Hartford. Sure enough, a few days ago I was driving along Maple Hollow when, glancing at the pond as I went by, I was struck by the lavender-purple color dominating the scene. I couldn’t stop that day but I went back this morning and was able to confirm that, yes, that lavender-purple color really was Purple Loosestrife that was now well-established along the banks of the pond. Already it was difficult to pick out other wildflowers among the sea of Purple Loosestrife. I walked across the bridge towards Gray Road and in the open field to my right I could pick out splashes of lavender-purple among the Queen Anne’s Lace.
It’s High Summer and, if left unchecked, the only color we will associate with this time of the year will be the lavender-purple of Purple Loosestrife, and what a shame that would be.
Other areas in town where I have seen Purple Loosestrife just beginning to establish its presence:
- Brodie Park South where 3-4 plants of Purple Loosestrife are in full bloom along the stone wall on the farther side of the meadow opposite the parking area;
- Callahan Park where a dozen or so plants are now blooming along the bank of the Farmington River bordered by Callahan Park.
Facts About Purple Loosestrife
Purple Loosestrife is an erect perennial herb in the loosestrife family (Lythraceae), growing to a height of 3-10 feet. Mature plants can have 1 to 50 4-sided stems that are green to purple and often branching making the plant bushy and woody in appearance. Opposite or whorled leaves are lance-shaped, stalk-less, and heart-shaped or rounded at the base. Plants are usually covered by a downy pubescence. Flowers are magenta-colored with five to seven petals and bloom from June to September. Seeds are borne in capsules that burst at maturity in late July or August. Single stems can produce an estimated two to three million seeds per year from a single rootstock. The root system consists of a large, woody taproot with fibrous rhizomes. Rhizomes spread rapidly to form dense mats that aid in plant production.
Purple Loosestrife is capable of invading wetlands such as freshwater wet meadows, tidal and non-tidal marshes, river and stream banks, pond edges, reservoirs, and ditches.
It spreads through the vast number of seeds dispersed by wind and water, and vegetatively through underground stems at a rate of about one foot per year. Seed banks can remain viable for twenty years. Purple loosestrife adapts to natural and disturbed wetlands. As it establishes and expands, it can out compete and replace native grasses, sedges, and other flowering plants that provide a higher quality source of nutrition for wildlife. The highly invasive nature of purple loosestrife allows it to form dense, homogeneous stands that restrict native wetland plant species, including some federally endangered orchids, and reduce habitat for waterfowl.
Control and Management:
- Manual: Small infestations of young Purple Loosestrife plants may be pulled by hand, preferably before seed set. Older plants can be removed with a shovel. Landfill or burn removed plants.
- Chemical: It can be effectively controlled using any of several readily available general use herbicides such as glyphosate or triclopyr. These herbicides may be most effective when applied late in the season when plants are preparing for dormancy. However, it may be best to do a mid-summer and a late season treatment, to reduce the amount of seed produced. Follow label and state requirements.
- Biological: For long term control of large infestations biological control is recommended. For more information see the downloadable USDA Fact Sheet below.
Download USDA Fact Sheet:
The above information on Purple Loosestrife and how to control this highly invasive perennial herb is excerpted from a USDA fact sheet published by the USDA. Download a copy of the complete fact sheet: Purple Loosestrife, USDA Fact Sheet (9).
Purple Loosestrife in Maple Hollow:
Purple Loosestrife in Brodie Park South
Purple Loosestrife along the banks of the Farmington River at Callahan Park