The storms last week were a reminder that spring is on the
way. That means pastures will be
greening as forages begin to put on spring growth. After such a wet winter, hoof traffic has
likely done some damage to your pastures no matter how careful you may have
been, and that leaves areas with thin stands of forage, or even bare ground, where
weeds will germinate. In some areas, you
may need to reseed, and now is the time for almost all of our common
forages. Check out the post from January
27 to choose the seed that is right for you.
No matter what though, some weeds will likely break through. Often times I get called to identify a weed
during the summer when they have reached 2 feet tall and are too large to
treat. The time to treat is in the
spring when weeds are small and still actively growing. Let’s take a look at a few common weeds with toxicity to horses.
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| Bulbous Buttercup |
Buttercup
Buttercup is a winter annual, so it will be present now as a
low growing weed with 3 parted leaves. As
spring arrives, it will begin to put on a thin stalk with a yellow flower. These cause increased salivation, decreased appetite, colic and diarrhea. In severe cases, poisoning can lead to
convulsions and death. Now is the time to control this weed before it puts on spring growth and flowers.
 |
| Cotyledon Stage Jimsonweed |
Jimsonweed
 |
| Jimsonweed |
A very
common weed in our area that is often ignored until several feet tall. Catching and treating this weed early will
prevent it from putting on seeds and being a chronic problem. Once large, the plant is easily identifiable
by it’s tree like shape with purple, trumpet shaped flowers, and spiny seed
pods. To catch it early look for a weed
germinating with initial cotyledons and leaves being long and slender, followed by leaves with
a more jagged edge and triangular points down the leaf margin. Crush a leaf in your hand, and there will be
a strong smell that some folks compare to a raw potato. Symptoms of poisoning include a weak but
rapid pulse, dilated pupils, dry mouth, incoordination, diarrhea, convulsions,
coma, and sometimes death.
Horse
Nettle and other Nightshades
 |
| Horse Nettle |
Horse
nettle is the most easily identified of the nightshades. It will be covered in spines on both leaves
and stems. Almost all of the nightshades
will have a leaf structure similar to jimsonweed, with a triangular shape and
jagged leaf margins, and many will have a purple tinge to the leaves,
particularly on the underside. Toxicity is
highest in the green berries of Horse Nettle, but the entire plant is toxic,
and spines can cause injury. Some symptoms
of nightshade poisoning include dilation of pupils, diarrhea, loss of appetite,
and loss of muscular coordination. You
may also notice mood changes, such as depression or apparent
hallucinations.
 |
| Pokeweed |
Pokeweed
Pokeweed
is often found along fence lines and again is often ignored until several feet
tall. Small plants are easily identified
by their large, oval, smooth leaves.
Many folks know this as poke salad, and some may even consume it. Despite that, this weed does have many toxic
properties that are more pronounced in older, mature plants. The weed is not very palatable, and horses
with access to a quality forage should avoid it. It is still a good idea to keep fence lines
clean and keep this weed out of your pastures.
Horses
will prefer a quality forage over all of the weeds mentioned here, and will
only be drawn to these weeds if options are limited. Problems with toxic weeds often arise in
times when forages are stressed from environmental conditions such as drought. All of these weeds can be controlled with a
broadleaf herbicide such as 2, 4-D or Dicamba, but remember these herbicides
will also kill clover and alfalfa in a mixed pasture. Talk to your extension agent for help
identifying weeds and choosing the right control option for your
situation.
For more
info on toxic plants, including toxic ornamentals, talk to your extension
agent, or visit https://njaes.rutgers.edu/pubs/fs938/
Photos
courtesy Virginia Tech Weed ID Guide, http://oak.ppws.vt.edu/~flessner/weedguide/
