50 Nebraskaland • October 2023
Invasive cattails haven't yet reached all the lakes and
wetlands across the state, but that result is starting to feel like
an inevitability. The best resistance strategy is to employ a
search-and-destroy tactic in wetlands where the invaders are
just starting to gain a foothold. Spot-spraying with aquatic-
labeled herbicides can kill the plants, but that needs to happen
when the fi rst small populations appear to prevent them from
mushrooming into massive hordes that defy easy solutions.
Once cattails have taken over a substantial portion of
a wetland, the objective of a land manager has to switch
from eradication to suppression. After several years of
establishment, those large populations seem to be immune to
complete destruction. Even a few stems that escape a control
treatment can quickly initiate a population recovery. More
importantly, cattails produce a tremendous amount of seed,
which can germinate and fi ll the space created by its now-
dead predecessors. Suppression of large cattail invasions, at
least as we currently understand the situation, is a long-term
commitment.
Two broad kinds of approaches are generally used to
suppress big masses of cattails. The fi rst is the use of an
aquatic-labeled herbicide to directly kill the plants. The
second is to reduce the storage of carbohydrates by the plants
and then either drown them or otherwise kill them when
they're weakened. Those two approaches can be combined, of
course, to enhance the eff ectiveness of herbicide treatments
by reducing the vigor of cattails before spraying them.
The use of herbicides often comes with collateral damage.
In many cases, the goal isn't simply to eradicate the cattails,
but to replace them with a more diverse plant community, at
least along wetland and stream banks. Spraying herbicides
that kill both the cattails and their potential replacements
isn't ideal, but it may sometimes be the best available option.
Most importantly, it's crucial to ensure that herbicides used
(and any surfactants or other additives) are labeled for
aquatic use and don't negatively impact wildlife, including
invertebrates, in the area.
The spring growth of cattails is fueled by carbohydrates
stored during the previous growing season. After that
pulse of spring growth depletes carbohydrate reserves, the
plants spend the rest of the summer trying to rebuild them.
Interrupting the summer growth of cattails with practices
such as repeated grazing, mowing, disking or others can
limit the reserves cattails carry into the winter. In playa
Narrowleaf cattail seeds at the Nature Conservancy's Platte River Prairies.
