Hi there, sweet clover is a biannual, if you seed it after a hard frost it will sprout next spring and produce blossoms the next year. I have planted mine in August (I am in eastern Ontario); it will take nicely and grow a couple of inches and give you blooms the next summer - so it's like you fooled it and are ahead one year. It is very tough and as long as it establishes it's root system in the fall it will make it through the winter. You should be able to get away with planting it now, like right now! After a couple of years of reseeding you will always have some in bloom, so don't worry about the biannual characteristic. Good luckI bought 10lbs of yellow sweet clover and 10lbs of white sweet clover when should I sow it for next spring, I am in south central MI. Do I wait until after the first hard frost?