sweet chestnut despite the mild winter

Sweet chestnut germinates after it has been affected by the frost. For several years I have been leaving sweet chestnuts in a pot outside, but with no effect.

This winter, the mildest for years, with hardly any decent frosts, and I am successful!

I am hoping to grow them in a large pot each, like large bonsai. Trying to find out when I can expect them to be producing sweet chestnuts!