So I had a problem getting Strawberry Seeds I usually get them around <Spring 4- (Yr.1) day after Sam comes < Spring 3- (Yr.1)>, so apparently after you buy the DLC crop (.99) one you will have to wait until Spring 16- (Yr.1) when you have at least
Spoiler:
I did have Andrea and Luke DLC purchased so... I ain't real sure if that had an effect on getting the Strawberry Seeds right away.