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Fireweed Cotrol
January , 2021
Taylor Davis, UF/IFAS Extension Highlands County
Here in Highlands County, fireweed is emerging everywhere and becoming a
nuisance for many of our livestock producers.
Fireweed is
a native winter annual species in Florida. It is typically seen in
north and central Florida on exposed areas within pastures (feeding troughs,
mineral feeders, under fence and tree lines (forage grass is less
prominent)).
Weed Structure
Fireweed has stinging hairs that hold a toxin that easily inserts into the
skin. When exposed to skin, the toxin creates irritation for several
hours. Cattle typically avoid this weed but horses are more likely to
try to browse this weed and can develop stress symptoms. Horses will
show weight loss, difficulty swallowing and breathing for several days after
grazing fireweed. In more severe cases, young horses have died from
rolling around in this weed (over exposure to toxins in stinging hairs).
Be careful, fireweed lives up to its name!
Fireweed’s leaves look similar to a strawberry plant, however the plant
itself does not strike any resemblance to a strawberry plant. They
have square stems, small pale green flower clusters, and the stinging hairs
are on the stems, petioles, and leaves. The hairs have a toxin that
contains irritants causing respiratory stress and allergic reactions when or
inhaled or ingested.
Weed Control
Historically, there is not much research on the control of fireweed. Recent
studies have been conducted to gauge the effectiveness of pasture herbicides
on this evil weed! Trials of 2,4 – D, Telar, Glyphosate, and Weedmaster were
carried out, but none were consistently effective for control. It is
recommended to use GrazonNext HL, Remedy Ultra, or Pasturegard HL for
control of fireweed. These herbicides can be applied anytime of the
year to warm-season forage grasses with no grazing restrictions for beef
cattle. Lactating dairy animals must be removed 0-14 days with
GrazonNext HL and Remedy Ultra, and completely removed for one season with
Pasturegard HL.
Many producers try to mow fireweed down, but this method does not control
this weed. It results in smaller plants with MORE stinging hairs.
The seed has a sticky substance coating that attach to the mower’s blades
for transport to non-infested areas, making the infestation worst.
Good News!
There is an unseen benefit! If you decide not to control fireweed,
typically around May, it will disappear due to the increase in temperature.
For more information on Fireweed control, click
here.
https://edis.ifas.ufl.edu/ag252