Manual/Mechanical control Manual or mechanical removal of exotic plants is the removal of plants by physical extraction such as pulling or cutting. This method is sometimes the only feasible control option, especially in sensitive environments where herbicide use would be too detrimental.
This may be as simple as cutting a tallow tree or removing a few objectionable plants that have just gotten started along the water margin. While cutting and removing a few plants by hand can be effective in small and limited areas, mechanical aquatic weed control on a large scale is generally difficult and expensive.
One mechanical technique, called a drawdown (removal of part of the water), can be effective and economical in controlling many kinds of aquatic weeds. However, there are many cases, such as in a natural system, where a drawdown is not feasible.
The Bayou Lafourche Freshwater District operates mechanical harvesters like this one to pull hydrilla from the water.