For this achievement you need to ship 15 of each crop, you only need to ship crops that you can buy its seeds from Pierre's and Sandy's.
Strawberries & Coffee Bean counts too, Strawberry seed can be purchased at the Egg Festival on the 13th of every Spring.
Coffee Been drop from Dust Sprites inside the mines.
Sapling fruits does not count towards the achievement, Sweet Gem Berry & Ancient Fruit does not count too.
and here the list you can buy from Pierre's and Sandy's shop: