It's another art work in the Unilever Series made exclusively for Tate Modern's Turbine Hall. Neither from far away nor from close proximity you can say the seeds are not real. You have to touch it.
The amount of work done is unbelievable (although if you bear in mind that the artist comes from China a lot more becomes possible) - more then 100 million live size seeds made from porcelain and hand painted by 1200 small craftsman over 2 year period.
It's a shame we missed a chance to walk over this vast "field" of sunflower seeds (it has been banned due to H&S as usually in UK :) ) but exhibition is still, needless to say, WORTH a visit.