Answer: I'm not sure whether the vetch would spread into your prairie area; you might contact your local Extension agent or state natural resources department for information specific to your area. There are other options for your ditch, however. Peaceful Valley Farm Supply, in Grass Valley, CA (Telephone # 916/272-4769) sells a variety of erosion control mixes , as well as some regional wildflower mixes and native perennial grasses that might be appropriate. Their catalog is full of useful information.
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