"Hairy vetch and common vetch are widely used as cool-season cover crops. They are annuals that can easily be killed when time comes to plant the main crop. Crown vetch is an extremely aggressive perennial that is used for erosion control, not as a cover crop."
"Common Name: Crown Vetch
Scientific Name: Securigera varia (L.) Lassen, formerly Coronilla varia L.
Legal Status: Restricted
Propagation and sale of this plant are prohibited in Minnesota. Transportation is only allowed when in compliance with Minnesota Statute 18.82. Although Restricted Noxious Weeds are not required to be controlled or eradicated by law, landowners are strongly encouraged to manage these invasive plants on their properties in order to reduce spread into new areas. Minnesota Noxious Weed Law."
We grow a lot of different plants at our farm, but I am NOT AN EXPERT on ground covers. However, I thought planting crown vetch was on the "naughty" list for most applications. (I do not know the advisory for Maine.)
I do have experience fighting invasive plants on our farm. It is NOT an enjoyable hobby.
My experience with Crown Vetch is that it is NOT a good competitor in fertile soil. Its not easy to establish in undisturbed soils. It really likes depleted and/or disturbed soils with little humus where it can stake the claim that few others can. In OK, the state highway department used it extensively to control erosion on highway cuts where it is very effective at holding soil. It has not taken over the tall grass prairie where there is little good habitat for it. It's really not the Russian thistle or hairy vetch kind of invasive. That said, if Maine prohibits it then don't use it.
