mint is easy to grown and really makes ice tea fabulous in the summer. it takes over pretty well so to me it isn't a garden plant but I planted it a couple of places in the yard and so always have some. ActuallyLavender is a plant....not so easy to grown in Minnesota as most varieties aren't winter hardy.
There is a co-op in St Cloud, Ralphie, that might be the closest to you. They will have that and other herbs in bulk, and you can get just as much as you want. Also online....
I pick yarrow, wormwood, mint, tansy and clover in the late summer and dry them. They munch on the clover but leave the others alone. I toss a couple of handfuls every now and then in the nest boxes in the winter. You can buy really pretty nest box blends with dried rose petals, caledula, etc but it is very pricey - maybe 12 bucks for a bowlful.
I did buy a forage blend for the chicken run - from peaceful gardens. It has clover, and I can't remember what else.....I'm going to block off an area and seed it, and not let them into it until it is going strong. Then I can block a different area off and seed that. About a mile down the road is a guy who lets his dogs run - has everyone in an uproar and lots of threats to shoot the **** dogs but so far no one has. Anyway, they come up here maybe once a week that I notice, so I keep the chickens locked up when I am not here. A couple of years ago the mother of his current dogs came and killed my entire flock except for one.