I have found that if you grow Sunflowers that have been started already at a Garden Center they just don't grow as tall as ones you plant from seed.I have grown many from both sources and the results are astounding!As far as 'Choco Sun' I have never grown it myself but it sounds close to the darker varieties included in the 'Autumn Glory' mix that I've grown for years...

Thanks omniphasic,

The plants I bought are 2 feet tall with a lot of buds and one has bloomed--it is yellow like your typical sunflower. But I guess it will not get 70 inches tall like I was told. I had already planted a whole package of seeds and not one germinated.

Betty