As of September 2, 2019, palmer amaranth seed has been added to South Dakota’s list of prohibited noxious weed seeds. Seed for sale within South Dakota may not contain prohibited noxious weed seeds, including palmer amaranth, in any amount.
Prohibited noxious weed seeds are highly destructive and difficult to control. Other prohibited noxious weed seeds include Canada thistle, field bindweed, hoary cress, horse nettle, leafy spurge, perennial sowthistle, and Russian knapweed.
Also, as of September 2, restricted noxious weed seeds cannot exceed a cumulative total of 20 per pound of seed. Restricted noxious weed seeds are highly objectionable and difficult to control in specific crops, fields, lawns, and gardens. Restricted noxious weed seeds include annual bluegrass, dodder, field pennycress, giant foxtail, hedge bindweed, musk thistle, plumeless thistle, quackgrass, spotted knapweed, wild carrot, wild mustard, and wild oats.
Additionally, seed for sale from bluestems, gramas, Indiangrass, and prairie sandreed may not contain weed seed more than three percent by weight. Seed for sale other than these grasses may not contain weed seed more than one percent by weight.
The South Dakota Department of Agriculture encourages those buying seed to carefully examine the labels of their seed purchases and ask to see the official seed analysis report if a percentage of weed seed is listed. Doing so will help deter the spread of weeds in South Dakota.