Curlyleaf Pondweed

Curlyleaf Pondweed (from MN DNR and MN UMN Extension)

Curlyleaf pondweed (CLP) is a rooted, submersed aquatic plant. Its color varies from olive-green to reddish-brown. It can reproduce via rhizomes or through seeds. The stems typically break the surface around June and the reproductive structure, called turions, look like pinecones and contain the seeds. CLP grows from the shore to 15-foot depths. It tolerates turbid water and will invade disturbed areas.

The CLP growing cycle is early in the year. The plant grows and break the surface, the turions mature and the seeds are spread, and the plant stems die off before mid-summer. Treatments must be done early in the year to catch the plant before the seeds mature.

Clearwater Lake has seen a substantial growth of CLP over the past few years. Delineation surveys were done in 2025 in areas reported by residents and those survey reports can be found below.

Curlyleaf Pondweed (CLP) Delineation Reports

2025: Blue Water Science conducted a CLP delineation survey on April 17, 2025. Below are the maps of the Delineation Reports and maps of the planned three treatment areas.

A full 2025 report is expected soon. Here is the full report from 2023: 2023 CLP & Milfoil Survey Report