Q: I have a plant that looks like a cattail, but it has a plume on top instead of a catkin. What is it?
Mike – Cottonwood, AZ
A: It sounds like you’ve got phragmites. Also known as “common reed,” certain invasive varieties of this plant have taken root on the East Coast, Midwest and Pacific Northwest – and, apparently, in your pond! To identify the species of phragmite in your pond, check out Cornell University’s “Morphological Differences” website here.
Generally speaking, phragmite is a perennial wetland grass that can grow to 6 to 15 feet in height. Its stems, which are erect, smooth and hollow, measure nearly 1 inch in diameter and are topped with 12-inch-long dense panicles, or purple-brown pyramid-shaped plumes of flowers, that emerge between July and September. The leaves that arise from the stem are 10 to 20 inches long and up to 2 inches wide.
The plants propagate mainly via an extensive network of underground rhizomes, or horizontal stems, that produce roots and shoots that grow as deep as 39 inches, with their root systems growing down another 3 feet. They’re hardy – and unfortunately, they can be tough to control.
A Substantial Threat
These invasive, non-native bad guys can do some serious damage to your lake or pond. Not only do they create tall, dense stands that crowd out native plants and animals, but they also block your shoreline views, create fire hazards from dry plant material, and reduce areas for swimming, fishing and hunting. They’re definitely not something you want on your property.
Once phragmites has taken root in your lake or pond, you’ll need to develop a long-term management plan to control them. Unfortunately, because the plants spread through their rhizomes, they could be difficult to eradicate entirely. That’s where chemical and mechanical control can help.
- Chemical control: First, you can spray an EPA-registered herbicide and surfactant product, like Shoreline Defense® & Treatment Booster™ PLUS Combo, in the late summer or early fall. Mix 8 ounces of Shoreline Defense®, 4 ounces of Treatment Booster™ PLUS and 2 gallons of water, pour it into pond sprayer and spray on the plants with your The Pond Guy® Pond Sprayer, completely wetting the surface of the leaves. Allow the mixture to absorb into the plant and the root system – the most difficult part of the plant to kill – for two weeks.
- Mechanical control: Once the herbicide has had a chance to soak into the phragmites’ root system and kill the plants, use a weed cutting and removal tool, like the Weed Cutter and Pond & Beach Rake, to slice at the base of the plants and remove them. If you can control your pond’s or lake’s water line, you can also cut the phragmites 2 to 3 inches below the water surface to cut off the plant’s supply of oxygen and drown the plant.
- Destroy what you’ve removed: To prevent the accidental spread of the plant, collect the cut material and bag it before disposing of it. In extreme cases, prescribed burning after herbicide treatment can provide additional control.
Before you begin, check with your local environmental agency to see if a permit is required for the treatments of these buggers. Plan to repeat this routine several years in a row. Patches may emerge even after regular treatments, but once you’ve wiped out the majority of the phragmites, the plant will be much easier to control. Just remember: early detection is key!
Pond Talk: How do you control phragmites in your lake or pond?