Since alpha packs has sold out from market the Devs is cooking something for players have something to do in the game.
And their answer is QUEST. By doing quest you can get the FERTI–PLUS, SPEED– GRO and MYSTERY SEED.
FERTI–PLUS - Doubles the chance to get 3* and 2* crops upon harvest for the land that it was applied to. This is applied across a land card for all its plots.
SPEED-GRO - Reduces the time required for a seed to mature by 10%-50% on a specific plot of land. This is applied across a land card for all its plots.
MYSTERY SEED - When you plant a mystery seed, it randomly transforms into a seed from the current season. The chance for it to transform to a certain rarity is the same as the drop rate for that seed in the packs. This means it has a 75% chance to be a Common seed and 0.8% to be a Legendary seed.