I bought some a few years ago and they were sown in a pot about April time and later planted outside. They have stayed in the garden for the last year and a half and are showing signs of life again now.
Good luck.

They really should be sown fresh and left to over winter, but get them in about half an inch deep and leave somewhere safe from mice and be patient, very patient, they can take years to grow.

Yes, they should be sown fresh as they rapidly die after a short time. No harm in trying I suppose. Mind, one point! They produce a root the first year and only shoot in their second spring so be patient.....if you are lucky and they have been kept cool in storage one or two may still be hanging on in there?