Lythrum salicaria or Purple loosestrife is a tough perennial that is characterized by its spiky pink-purple flowers. The plant was brought to the north-eastern United States in the 18th century by early settlers for their flower garden. Since then, it has spread aggressively across the United States and Canada.
The real problem
Wetlands are a biologically diverse component of the ecosystem with hundreds of varieties of fish, amphibians, plants, mammals, birds, reptiles, and insects relying on healthy riparian for their survival. Purple loosestrife grows rapidly in wetlands and the native species that thrive and reproduce there gets quickly covered under a swarm of purple flowers. Thousands of hectares of fertile wetlands that yield wild rice and support fish population are degraded in North America every year, with economic losses running into millions of dollars.
It can invade parched sites too. The plant has encroached agricultural as well as pasture land making it difficult for beneficial crops and animals to survive.
Why is it such a menace?
Purple loosestrife can produce countless seeds which disperse easily through wind and water. Thick stretches cover thousands of acres that eliminate open aquatic territory for species such as rare amphibians and butterflies. When it was brought from its native continent to New England, its natural predators were left behind. The predators prevented population explosion of Purple loosestrife in the native continent. However, due to lack of its natural enemies such as a beetle in the U.S.; purple loosestrife population has grown considerably.
How can you control Purple Loosestrife?
It is important to control for protecting native wildlife. Implementing proper control methods can inhibit the spread of the plant. The simple guidelines mentioned below can help in controlling the spread of purple loosestrife:
• The most appropriate time to manage is its flowering season that is in between late June, July and early August.
• Physical removal and registered herbicides can control small population of purple loosestrife.
• Once the area gets too heavily infested, it might become extremely difficult to physically remove the plant. In that case, control techniques can be used to control growth that may occur due to seeds dispersal.
• Watch drains or streams running from infested sections, as new colonies can easily sprout there. Cutting or digging out plants in the areas with manageable infestations will control the spread beyond the area.
• Biological control is another effective method to control invasive population. This method involved reuniting the plant with its natural predators. There are several species of insects that can feed and reduce purple loosestrife invasion.
Are there any alternative plants that can be sown?
There is an abundant variety of garden perennials that despite sharing similarities with purple loosestrife do not pose any threat to the natural surroundings. Some of the eco-friendly alternatives such as Blazing Star, Gay Feather, Delphinium, False Spirea, Foxglove, etc. are easily available at local nurseries.
Several agencies in the North America have initiated efforts to raise awareness about controlling the spread of this plant. Federal wildlife services, environment agencies, and conservation communities have come together to prevent the spread of this invasive plant.