Michigan Aquatic Weed Control and Pond Management

Lake Michigan has been subject to invasions of aquatic weeds species since the settlement of the region by Europeans. Since the 1800s, at least 140 non-indigenous aquatic organisms have been introduced to the Great Lakes ecosystem. Aquatic weeds come in the form of flora and fauna, and here we focus on the six most widespread pond weeds in Michigan that have led to efforts to engage in ongoing pond weed control and management.

Purple Loosestrife

Purple Loosestrife (Lythrum salicaria) is a wetland plant from Europe and Asia. It was introduced to the east coast of North America in the 1800s as it spread along roads, canals and drainage ditches. Later distributed as an ornamental, this exotic plant is in Michigan, 39 other states and all Canadian border provinces.

The plant can form dense, impenetrable stands that are unsuitable as cover, food or nesting sites for a wide range of native wetland animals, including ducks, geese, rails, bitterns, muskrats, frogs, toads and turtles. Many rare and endangered wetland plants and animals also are at risk.

Purple loosestrife thrives on disturbed, moist soils, often invading after some type of construction activity. Eradicating an established stand is difficult because of an enormous number of seeds in the soil. One adult can disperse 2 million seeds annually. The plant is able to re-sprout from roots and broken stems that fall to the ground or into the water. TheOpen Water kit is an effective answer for controlling purple loosestrife and other aquatic weeds in Michigan.


Coontail (Ceratophyllum demersum) is a completely submersed plant commonly seen in Michigan lakes with moderate to high nutrient levels. It is also known by the common name hornwort. The common names refer to its full, bottle-brush-like growth form and its forked, antler-shaped leaves. The Latin name Ceratophyllum pertains to the horned leaf edges – Cerato derives from the Greek word “keras” (horn, as in rhinoceros). Phyllum means leaf.

The serrated, forked leaves of coontail are arranged on the stems in whorls, with usually 5-12 leaves in each whorl. It is generally a dark, olive green color, and is often rather hard and crusty to the feel. This is especially true where it grows in hard water lakes (the calcium in the water becomes deposited on the leaf surface, making it seem crunchy). To control Coontail and other aquatic weeds in your Michigan pond, PondRestore Ultra pond weed control kit is highly effective.


Phragmites (Phragmites australis) is an aggressive-growing, exotic emergent plant that is infesting Michigan’s coastal areas, wetlands, and lake shores. Plants can exceed 15 feet in height and obstruct shoreline views and uses. Phragmites can greatly reduce the diversity of desirable native plants, including the native variety of Phragmites, and reduce wildlife habitat.

Primary growth occurs during mid-summer with flowering and seed dispersal in late summer and fall. Besides seed dispersal, Phragmites can also spread through the expansion of underground stems called rhizomes. In fact, much of the plant’s biomass is underground. Rhizomes can exceed 60 feet in length, grow several feet per year, and readily grow into new plants when fragmented. Phragmites roots can penetrate the ground several feet and the plant can survive in relatively dry uplands as well as shallow wetlands. However, water depths greater than a few inches typically inhibit Phragmites seed germination.

Phragmite control in Michigan lakes and ponds is effective with the help of anOpen Water kit sprayed directly onto the plants.

Eurasian Water Milfoil

Eurasian Water Milfoil (Myriophyllum Spicatum) first appeared in Michigan over fifty years ago and has since infested several thousand inland lakes. This highly aggressive rooted aquatic plant prefers the soft, mucky bottoms of lakes with moderate to high biologic productivity.

Early detection and management utilizing aquatic herbicides or milfoil weevils are critical in controlling this rapidly propagating foreign invasive aquatic plant species.We recommend using treatments once plants are established but before flowering occurs. RestoreAccess Ultra is perfect for Milfoil eradication in Michigan ponds and lakes.

Curly-Leaf Pond Weed

First observed in Michigan inland lakes over one hundred years ago, Curly‐Leaf Pondweed (Potomogeton Crispus) is one of the first aquatic weeds to have entered Michigan’s waters. Curly‐leaf pondweed is an aggressive macrophyte plant that begins to grow rapidly in the spring, often forming dense mats that interfere with recreational boating. The plant typically grows in eight to ten feet of waters. To effectively control Curly-Leaf aquatic weed invasion, use RestoreAccess Ultra.


Naiads (Najas spp.) are slender, narrow-leaved aquatic weeds that grow completely underwater and are rooted to the bottom of lakes and ponds. The leaves have finely toothed edges and occur in pairs or whorls, and each leaf base forms a sheath around the stem. A key characteristic is the presence of tiny, greenish flowers at the bases of the leaves.These plants may be hard to distinguish from some narrow-leaved pond weeds and other plants, but naiads never have broad, floating leaves or conspicuous flowers or seed heads. Either RestoreAccess Ultra or a good dose of Hydrothol 191 will allow you to control Naiads in your Michigan pond or lake.