Download The Enemy: Horseradish (Amoracia rusticana)

The Enemy: Horseradish (Amoracia rusticana)
Strategy: This European native was introduced as a desirable forage grown commercially or in small
gardens. This cabbage like plant is quite desirable by most people and can be medicinally used. It has a
long somewhat narrow leaves with a prominent white midvein that grows out of a long slender root. It
generally grows to a height of 2 feet, but I have seen it up to 6 foot tall if left unchecked. The root is the
desirable part of the plant. It produces a small white flower, producing numerous seeds, but generally
this plant spreads by the roots. This is accomplished by the root being split apart and moved to another
field in the soil or by spreading by underground roots to adjacent properties. I have seen a few pastures
south of Idaho Falls with this as a weed and our neighbors in Clark County have a numerous pastures
with it as a weed.
Attack: Contrary to its name, this plant is actually toxic to horses. Once the plant starts to spread it
continues to get worse as the livestock eats everything around it which perpetuates its growth. As has a
deep spreading root it can take up all the water and nutrients that are utilized for the desirables to
flourish.
Defense: With most perennial plants, mechanical control is not effective. The only animals that will eat
on the plants are grasshoppers. Roundup and 2,4-D are not effective, but do a great job of killing off the
desirable grasses!!! As this is a plant in the cabbage family a couple of herbicides that could be utilized
would be Opensite, Redeem, or Turflon II (the last two contain triclopyr). Timing of application should
be after the first 28 degree frost in the fall.