Field Note: Scouringrush Management
Scouringrush is generally found in moist areas around marshlands and margins of ponds or lakes. These problem weeds can invade wetter low lying areas of fields and spread very quickly. Scouringrush can be especially problematic in pasture and hay fields as it produces alkaloids that can be toxic to livestock, especially horses.
Control of Scouringrush can be difficult, as it spreads through both rhizomes and spores. The top growth can be easily controlled through mechanical tillage or by burning, but due to it’s deep rhizomes, it re-establishes very quickly. When cut, the tuberous root system can become a new plant, making tillage a potentially less viable option unless continuous tillage is used. Drying out the areas impacted by Scouringrush seems to be very effective through tile drainage or continuous tillage.
Chemical control options for Scouringrush include applications of 2,4-D often. Thankfully, it generally is quickly outrun by row crops and in grass crops can be suppressed by applications of nitrogen, which Scouringrush doesn’t respond to, but grass crops respond quickly.