IRVM: WildflowersThere is a drastic difference between the weeds listed as noxious by the state of Iowa and those that are actual prairie wildflowers. The weeds listed in the previous section spread and grow quickly, they have adapted to survive cultivation and in some cases, they have become tolerant to herbicide treatments. These are the reasons that they are considered noxious.
On the other hand, wildflowers are slow growing, do not tolerate cultivation, spread slowly and do not tolerate herbicide. They are NOT a threat for invading agricultural fields.
So, please do not confuse wildflowers and weeds. Wildflowers have been here since the beginning. They existed in these grasslands thousands of years ago. Most weeds only became prominent with the advent of row-crop agriculture.
Most weeds also come from other countries, unlike wildflowers which are native to Iowa. Many of our weeds we owe to other countries or some poor, misled soul who thought that the plant would make a nice addition to a flower garden (another Euopean idea).
For example, Multiflora Rose comes from Japan. Canada Thistles have nothing to do with Canada and Canada Geese do not spread the seeds as some will try to tell you. Canada Thistle came to us in hay brought over for horses during the Revolutionary War.
Musk Thistles come to us from the grasslands of Europe and Asia where a small weevil that we do not have in this country occurs naturally and helps to keep the numbers down by eating the seed heads and killing the plant. They come to this country and have no competition or predators and are immensely successful. All weeds have a history... the point is they didn't start out here and they are here due to a lack of human foresight.
Native wildflowers on the other hand belong here. They are adapted to live in these grassland eco-systems and they will be successful if we allow them to be.