It only costs money if you want them to send you the seeds. It's free to get email about what to plant when.
From my list: I wish I were transplanting tomatoes, but that would require me to have started some from seed a while back! I wonder if it reminds you to do that...
I just tried to sign up for the "freebie" and left it running for 1 hr 10 mins and it never created my calendar. It being a Beta program, maybe they still have some bugs to work out.