The Exotic Plants are obtained from the Seedling Kit. This Kit is granted once you progress enough through the Conservatory. You should have it on your Board, in the Inventory, or in the Pocket below the Board.
To use the Seedling Kit, you need to sink a Shovel and a Golden Seed into the kit.
Shovels can be obtained from Gardening Barrels.
To obtain the Golden Seed, you need to Produce Large Seed Bags from the Flower Pots, then, empty the content of the Large Seed Bag to obtain an Empty Seed Bag. Merge two Level 4 Empty Seed Bags to achieve your golden seed.
