If you deleted Flower Garden or transferred it to another phone, you can restore previous Flower Shop purchases.
Go to the Flower Shop, tap the top left button (settings), and select “Restore Purchases”. For this to work you need to be logged in to the same iTunes account you originally bought them from. You also can only restore purchases from the same app you originally bought them from (Flower Garden or Flower Garden Free).
This applies only to gardens and seeds. Fertilizer is a consumable item, so it can’t be restored this way.
New in update 2.83:
If you delete Flower Garden from your device and reinstall it in the same device, when you restore purchases, in addition to App Store purchases, it will also restore purchases made with credits, credit total, and fertilizer total.