I guess I never timed it, and I think it only produces tubers sometimes. Don't know what 'sometimes' means actually, but I guess mine must 'cause it comes back from dormancy just fine. I've even grown it in the ground outside and had it come back, except for the year it didn't. It's not one of the ones that's supposed to be hardy, but it gets so big (and so beautiful) in the ground in our heat and humidity that I like to grow them that way. A few weeks ago I started a cutting to grow in the house for insurance; haven't decided yet if I'll be able to find space for the big one inside. I've been growing it for at least fifteen or twenty years I think, and I don't remember ever seeing seeds, tho' I don't know that I was looking for them particularly. The flowers are very pretty but fleeting, but the bright calyxes stay on for a long time. It doesn't like temperatures much below 60F, and really will only take them that low if they've been outside all summer as mine always are. Oh--they don't need to go dormant if you don't want them to, but they do need a lot of light. The best one I ever grew I think was in quite a bit more sun than I realized when I first planted it there, but it did mch better than various ones I'd planted in shadier spots.Great plant!