Purple loosestrife is a tall, multi-stemmed (30-50 per plant), perennial forb that can grow up to 10 ft. (3 m) in height. The opposite or whorled leaves are dark-green, lance-shaped, sessile, 1.5-4 in. (3.8-10.2 cm) long and round or heart-shaped at the base. Flowering occurs in July to October, when pink to purplish flowers develop in 4-16 in. (10.2-40.6 cm) long spikes at the tops of the stems. Flowers have 5-7 petals and twice as many stamens as petals. Fruits are capsules that are enclosed in the hairy sepals. Purple loosestrife is a serious invader of many types of wetlands, including wet meadows, prairie potholes, river and stream banks, lake shores, tidal and non-tidal marshes, and ditches. It can quickly form dense stands that displace native vegetation. Purple loosestrife can spread very rapidly due to its prolific seed production; one plant can produce as many as 2 million seeds per year. Purple loosestrife is native to Europe and Asia. It was first introduced into North America in the early 1800s for ornamental and medicinal purposes. It has also been used as a nectar plant for bee-keeping. (Source: EDDMapS)
Management Options:
A. Hand Pulling
Control can often be accomplished by hand-pulling for small populations (less than 1/4 acre). Plants pulled early in the season are much smaller and easier to manage.
B. Cutting & Mowing
Mowing (or brush hogging where woody plants are present) is suited to non-rocky, open areas that are not too steep for the equipment. Obviously, mowing affects all plants mowed, not just the target species. Equipment should be cleaned prior to being brought to the site and should be thoroughly cleaned of all seeds and plant parts before leaving the site.
C. Propane Torch
Backpack-mounted propane torches can be used for invasive plant control. This method uses targeted fire to heat the base of a plant, killing it. Some plants with developed roots may resprout after this treatment. Safety training is needed before using this method.
D. Herbicides
Herbicides are pesticides used for vegetation management. Herbicides can be a valuable tool in controlling invasive species, but they must be used with caution.
Always read the entire herbicide label and apply herbicides according to label directions. Wear the personal protective equipment specified on the product label and heed any and all environmental restrictions stated on the label.
Most herbicide products, especially those marketed to homeowners and small property owners, are classified as “General Use” pesticides. Only licensed pesticide applicators are allowed to purchase or apply “Restricted Use” pesticides.
E. Grazing
Grazing means using animals to eat plants.