The Best Time to Treat Curly-Leaf Pondweed: Stop This Invasive Weed Before It Spreads!

Curly-leaf pondweed (Potamogeton crispus) is an invasive submerged aquatic plant easily identified by its green leaves with a reddish hue and distinctive wavy, crinkled edges. Originally native to Eurasia, this species was introduced to North America in the mid-1800s and has since spread rapidly, outcompeting native aquatic vegetation. Without proper management, it can quickly dominate a waterbody, reducing biodiversity, degrading water quality, and interfering with recreational activities like fishing, swimming, and boating. Effective curly-leaf pondweed control requires a strategic approach, with a strong emphasis on selective herbicide application for long-term management.

What Makes Curly-Leaf Pondweed a Problem?

Curly-leaf pondweed thrives in cooler water temperatures, giving it a significant advantage over native plants. It begins growing in late fall and early spring, when most other aquatic vegetation remains dormant. By the time native plants start emerging, curly-leaf pondweed has already formed dense underwater mats, blocking sunlight and limiting the growth of beneficial species. This competitive edge allows it to rapidly take over lakes and ponds, reducing plant diversity and altering ecosystems. By midsummer, it often dies back, leaving behind dense mats of decomposing vegetation that can degrade water quality and reduce dissolved oxygen.

Unlike many native aquatic plants, curly-leaf pondweed spreads aggressively through turions (seed-like buds), which settle in sediment and sprout the following season. These turions can remain dormant for years, making eradication difficult. Without appropriate intervention, curly-leaf pondweed poses a serious threat to lakes and ponds, by altering the ecological balance of a waterbody.

Invasive Aquatic Species Impact Lakes and Ponds By:

• Disrupting Native Ecosystems – Outcompeting native plants, reducing biodiversity, and harming fish habitats.

• Altering Water Quality – Dense growth reduces water flow and increases organic decay, leading to oxygen depletion and algae blooms.

• Interfering with Recreation – Thick underwater mats make boating, swimming, and fishing difficult or impossible.

• Spreading Uncontrollably – Small fragments and turions allow curly-leaf pondweed to spread rapidly, requiring long-term management strategies.

Curly-leaf pondweed is easily recognizable by its distinctive wavy, crinkled leaves.

Unlike many aquatic plants, curly-leaf pondweed thrives in early spring and dies off by midsummer.

The Importance of Treating Curly-Leaf Pondweed at the Right Time

One of the biggest challenges with curly-leaf pondweed management is its unique growth cycle. Unlike many aquatic plants, curly-leaf pondweed thrives in early spring and dies off by midsummer. As it decomposes, it releases large amounts of organic matter, which fuels algae blooms and drops oxygen levels, creating poor water quality conditions that can lead to fish kills. This is why proper timing is crucial—treating too late can make the problem worse.

The most effective way to control curly-leaf pondweed is to apply selective herbicides in early spring when water temperatures are between 50-60°F. Treating at this stage ensures the herbicide stops the plant before it produces turions, reducing the likelihood of reinfestation the following year. Waiting until midsummer is ineffective because the plant has already spread its seeds and is beginning to decay, contributing to poor water conditions.

How Our Biologists Help 

Applying herbicides at the right time is critical for effective control. This is where our expert biologists come into play—carefully monitoring water temperatures and plant development to ensure treatment is applied at the most effective moment. By interrupting the plant’s growth cycle before it spreads turions, we help restore balance to your pond or lake and prevent future outbreaks.

If you're struggling with curly-leaf pondweed, professional aquatic herbicide treatments can provide effective, long-term solutions. Our team specializes in customized pond and lake management plans, ensuring that your water remains healthy, clear, and free from invasive weeds.

About Jones Lake Management
Since 1949, Jones Lake Management has been a trusted leader in lake and pond management, delivering scientifically backed solutions to create and maintain healthy, balanced, and beautiful waterbodies. Our expert team offers a full range of services, including fish stocking, fisheries management, water quality monitoring, algae and aquatic weed control, aeration solutions, erosion control, invasive species management, hydraulic dredging, and more. Whether you manage a private lake, an HOA stormwater pond, a golf course water feature, or a municipal waterway, we provide customized solutions to ensure your waterbody remains healthy, functional, and thriving.